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HDF5/H5T API Specification
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And in this document, the 
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;&nbsp;
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<a href="RM_H5.html">H5</a>&nbsp;&nbsp;
<a href="RM_H5A.html">H5A</a>&nbsp;&nbsp;
<a href="RM_H5D.html">H5D</a>&nbsp;&nbsp;
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<a href="RM_H5G.html">H5G</a>&nbsp;&nbsp;
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<a href="RM_H5R.html">H5R</a>&nbsp;&nbsp;
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H5T&nbsp;&nbsp;
<a href="RM_H5Z.html">H5Z</a>&nbsp;&nbsp;
<a href="Tools.html">Tools</a>&nbsp;&nbsp;
<a href="PredefDTypes.html">Datatypes</a>&nbsp;&nbsp;
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<center>
<h1>H5T: Datatype Interface</h1>
</center>

<h2>Datatype Object API Functions</h2>

These functions create and manipulate the datatype which describes elements
of a dataset.


<p>
<strong>The C Interfaces:</strong>

<table border=0>
<tr><td valign=top>
<i>General Datatype Operations</i>
    <li><a href="#Datatype-Create">H5Tcreate</a>
    <li><a href="#Datatype-Open">H5Topen</a>
    <li><a href="#Datatype-Commit">H5Tcommit</a>
    <li><a href="#Datatype-Committed">H5Tcommitted</a>
    <li><a href="#Datatype-Copy">H5Tcopy</a>
    <li><a href="#Datatype-Equal">H5Tequal</a>
    <li><a href="#Datatype-Lock">H5Tlock</a>
    <li><a href="#Datatype-GetClass">H5Tget_class</a>
    <li><a href="#Datatype-GetSize">H5Tget_size</a>
    <li><a href="#Datatype-GetSuper">H5Tget_super</a>
    <li><a href="#Datatype-Close">H5Tclose</a>
<p>
<i>Conversion Functions</i>
    <li><a href="#Datatype-Convert">H5Tconvert</a>
    <li><a href="#Datatype-Find">H5Tfind</a>
    <li><a href="#Datatype-SetOverflow">H5Tset_overflow</a>
    <li><a href="#Datatype-GetOverflow">H5Tget_overflow</a>
    <li><a href="#Datatype-Register">H5Tregister</a>
    <li><a href="#Datatype-Unregister">H5Tunregister</a>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top>
<i>Atomic Datatype Properties</i>
  <table><tr><td valign=top>
    <li><a href="#Datatype-SetSize">H5Tset_size</a>
    <li><a href="#Datatype-GetOrder">H5Tget_order</a>
    <li><a href="#Datatype-SetOrder">H5Tset_order</a>
    <li><a href="#Datatype-GetPrecision">H5Tget_precision</a>
    <li><a href="#Datatype-SetPrecision">H5Tset_precision</a>
    <li><a href="#Datatype-GetOffset">H5Tget_offset</a>
    <li><a href="#Datatype-SetOffset">H5Tset_offset</a>
    <li><a href="#Datatype-GetPad">H5Tget_pad</a>
    <li><a href="#Datatype-SetPad">H5Tset_pad</a>
    <li><a href="#Datatype-GetSign">H5Tget_sign</a>
    <li><a href="#Datatype-SetSign">H5Tset_sign</a>
  </td><td valign=top>
    <li><a href="#Datatype-GetFields">H5Tget_fields</a>
    <li><a href="#Datatype-SetFields">H5Tset_fields</a>
    <li><a href="#Datatype-GetEbias">H5Tget_ebias</a>
    <li><a href="#Datatype-SetEbias">H5Tset_ebias</a>
    <li><a href="#Datatype-GetNorm">H5Tget_norm</a>
    <li><a href="#Datatype-SetNorm">H5Tset_norm</a>
    <li><a href="#Datatype-GetInpad">H5Tget_inpad</a>
    <li><a href="#Datatype-SetInpad">H5Tset_inpad</a>
    <li><a href="#Datatype-GetCset">H5Tget_cset</a>
    <li><a href="#Datatype-SetCset">H5Tset_cset</a>
    <li><a href="#Datatype-GetStrpad">H5Tget_strpad</a>
    <li><a href="#Datatype-SetStrpad">H5Tset_strpad</a>
  </td></tr></table>
<p>
<i>Enumeration Datatypes</i>
    <li><a href="#Datatype-EnumCreate">H5Tenum_create</a>
    <li><a href="#Datatype-EnumInsert">H5Tenum_insert</a>
    <li><a href="#Datatype-EnumNameOf">H5Tenum_nameof</a>
    <li><a href="#Datatype-EnumValueOf">H5Tenum_valueof</a>
    <li><a href="#Datatype-GetMemberValue">H5Tget_member_value</a>
    <li><a href="#Datatype-GetNmembers">H5Tget_nmembers</a>
    <li><a href="#Datatype-GetMemberName">H5Tget_member_name</a>
    <li><a href="#Datatype-GetMemberIndex">H5Tget_member_index</a>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top>
<i>Compound Datatype Properties</i>
    <li><a href="#Datatype-GetNmembers">H5Tget_nmembers</a>
    <li><a href="#Datatype-GetMemberClass">H5Tget_member_class</a>
    <li><a href="#Datatype-GetMemberName">H5Tget_member_name</a>
    <li><a href="#Datatype-GetMemberIndex">H5Tget_member_index</a>
    <li><a href="#Datatype-GetMemberOffset">H5Tget_member_offset</a>
    <li><a href="#Datatype-GetMemberType">H5Tget_member_type</a>
    <li><a href="#Datatype-Insert">H5Tinsert</a>
    <li><a href="#Datatype-Pack">H5Tpack</a>
<p>
<i>Array Datatypes</i>
    <li><a href="#Datatype-ArrayCreate">H5Tarray_create</a>
    <li><a href="#Datatype-GetArrayNdims">H5Tget_array_ndims</a>
    <li><a href="#Datatype-GetArrayDims">H5Tget_array_dims</a>
<p>
<i>Variable-length Datatypes</i>
    <li><a href="#Datatype-VLCreate">H5Tvlen_create</a>
<p>
<i>Opaque Datatypes</i>
    <li><a href="#Datatype-SetTag">H5Tset_tag</a>
    <li><a href="#Datatype-GetTag">H5Tget_tag</a>
</td></tr>
</table>

<p>
<strong>The FORTRAN90 Interfaces:</strong>
<br>

<font size=-1>
<i>In general, each FORTRAN90 subroutine performs exactly the same task 
as the corresponding C function.  The links below go to the C function 
descriptions, which serve as general descriptions for both.  A button, 
under <strong>Non-C API(s)</strong> at the end of the C function description,
opens an external browser window displaying the FORTRAN90-specific 
information.  You will probably want to adjust the size and location of 
this external window so that both browser windows are visible and to 
facilitate moving easily between them.</i>
</font>

<table border=0>
<tr><td valign=top width=32%>
<i>General Datatype Operations</i>
    <li><a href="#Datatype-Create">h5tcreate_f</a>
    <li><a href="#Datatype-Open">h5topen_f</a>
    <li><a href="#Datatype-Commit">h5tcommit_f</a>
    <li><a href="#Datatype-Committed">h5tcommitted_f</a>
    <li><a href="#Datatype-Copy">h5tcopy_f</a>
    <li><a href="#Datatype-Equal">h5tequal_f</a>
<!--<li><a href="#Datatype-Lock">h5tlock_f</a>                          -->
    <li><a href="#Datatype-GetClass">h5tget_class_f</a>
    <li><a href="#Datatype-GetSize">h5tget_size_f</a>
<!--<li><a href="#Datatype-GetSuper">h5tget_super_f</a>                 -->
    <li><a href="#Datatype-Close">h5tclose_f</a>
<!--<p>                                                                     -->
<!--<i>Conversion Functions</i>                                             -->
<!--<li><a href="#Datatype-Convert">h5tconvert_f</a>                    -->
<!--<li><a href="#Datatype-Find">h5tfind_f</a>                          -->
<!--<li><a href="#Datatype-SetOverflow">h5tset_overflow_f</a>           -->
<!--<li><a href="#Datatype-GetOverflow">h5tget_overflow_f</a>           -->
<!--<li><a href="#Datatype-Register">h5tregister_f</a>                  -->
<!--<li><a href="#Datatype-Unregister">h5tunregister_f</a>              -->
    <p>
<i>Atomic Datatype Properties</i>
    <li><a href="#Datatype-SetSize">h5tset_size_f</a>
    <li><a href="#Datatype-GetOrder">h5tget_order_f</a>
    <li><a href="#Datatype-SetOrder">h5tset_order_f</a>
    <li><a href="#Datatype-GetPrecision">h5tget_precision_f</a>
    <li><a href="#Datatype-SetPrecision">h5tset_precision_f</a>
    <li><a href="#Datatype-GetOffset">h5tget_offset_f</a>
    <li><a href="#Datatype-SetOffset">h5tset_offset_f</a>
</td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top width=32%>
<i>Atomic (continued)</i>
<!--  <table><tr><td valign=top>                                            -->
    <li><a href="#Datatype-GetPad">h5tget_pad_f</a>
    <li><a href="#Datatype-SetPad">h5tset_pad_f</a>
    <li><a href="#Datatype-GetSign">h5tget_sign_f</a>
    <li><a href="#Datatype-SetSign">h5tset_sign_f</a>
    <li><a href="#Datatype-GetFields">h5tget_fields_f</a>
    <li><a href="#Datatype-SetFields">h5tset_fields_f</a>
    <li><a href="#Datatype-GetEbias">h5tget_ebiass_f</a>
    <li><a href="#Datatype-SetEbias">h5tset_ebiass_f</a>
<!--  </td><td valign=top>                                                  -->
    <li><a href="#Datatype-GetNorm">h5tget_norm_f</a>
    <li><a href="#Datatype-SetNorm">h5tset_norm_f</a>
    <li><a href="#Datatype-GetInpad">h5tget_inpad_f</a>
    <li><a href="#Datatype-SetInpad">h5tset_inpad_f</a>
    <li><a href="#Datatype-GetCset">h5tget_cset_f</a>
    <li><a href="#Datatype-SetCset">h5tset_cset_f</a>
    <li><a href="#Datatype-GetStrpad">h5tget_strpad_f</a>
    <li><a href="#Datatype-SetStrpad">h5tset_strpad_f</a>
<!--  </td></tr></table>                                                    -->
<!--<p>                                                                     -->
<!--<i>Array Datatypes</i>
<!--    <li><a href="#Datatype-ArrayCreate">H5Tarray_create</a>             -->
<!--    <li><a href="#Datatype-GetArrayNdims">H5Tget_array_ndims</a>        -->
<!--    <li><a href="#Datatype-GetArrayDims">H5Tget_array_dims</a>          -->
<!--<p>                                                                     -->
<!--<i>Variable-length Datatypes</i>                                        -->
<!--<li><a href="#Datatype-VLCreate">h5tvlen_create_f</a>               -->
    </td><td>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</td><td valign=top width=32%>
    <i>Compound Datatype Properties</i>
    <li><a href="#Datatype-GetNmembers">h5tget_nmembers_f</a>
<!--<li><a href="#Datatype-GetMemberClass">H5Tget_member_class_f</a>        -->
    <li><a href="#Datatype-GetMemberName">h5tget_member_name_f</a>
<!--<li><a href="#Datatype-GetMemberIndex">h5tget_member_index_f</a>      -->
    <li><a href="#Datatype-GetMemberOffset">h5tget_member_offset_f</a>
<!--<li><a href="#Datatype-GetMemberDims">h5tget_member_dims_f</a>          -->
    <li><a href="#Datatype-GetMemberType">h5tget_member_type_f</a>
    <li><a href="#Datatype-Insert">h5tinsert_f</a>
    <li><a href="#Datatype-Pack">h5tpack_f</a>
<!--<li><a href="#Datatype-InsertArray">h5tinsert_array_f</a>               -->
    <p>
    <i>Enumeration Datatypes</i>
    <li><a href="#Datatype-EnumCreate">h5tenum_create_f</a>
    <li><a href="#Datatype-EnumInsert">h5tenum_insert_f</a>
    <li><a href="#Datatype-EnumNameOf">h5tenum_nameof_f</a>
    <li><a href="#Datatype-EnumValueOf">h5tenum_valueof_f</a>
    <li><a href="#Datatype-GetMemberValue">h5tget_member_value_f</a>
    <li><a href="#Datatype-GetNmembers">h5tget_nmembers_f</a>
    <li><a href="#Datatype-GetMemberName">h5tget_member_name_f</a>
<!--<li><a href="#Datatype-GetMemberIndex">h5tget_member_index_f</a>      -->
    <p>
    <i>Opaque Datatypes</i>
    <li><a href="#Datatype-SetTag">h5tset_tag_f</a>
    <li><a href="#Datatype-GetTag">h5tget_tag_f</a>
</td></tr>
</table>


<p>
The Datatype interface, H5T, provides a mechanism to describe the
      storage format of individual data points of a data set and is
      hopefully designed in such a way as to allow new features to be
      easily added without disrupting applications that use the data
      type interface.  A dataset (the H5D interface) is composed of a
      collection or raw data points of homogeneous type organized
      according to the data space (the H5S interface).

<p>
A datatype is a collection of datatype properties, all of
      which can be stored on disk, and which when taken as a whole,
      provide complete information for data conversion to or from that
      datatype.  The interface provides functions to set and query
      properties of a datatype.
      
<p>
A <em>data point</em> is an instance of a <em>datatype</em>,
      which is an instance of a <em>type class</em>.  We have defined
      a set of type classes and properties which can be extended at a
      later time.  The atomic type classes are those which describe
      types which cannot be decomposed at the datatype interface
      level; all other classes are compound.

<p>
See <a href="Datatypes.html"><cite>The Datatype Interface (H5T)</cite></a>
in the <cite>HDF5 User's Guide</cite> for further information, including a complete list of all supported datatypes.


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Open">H5Topen</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t</em><code>H5Topen</code>(<em>hid_t</em> <code>loc_id</code>,
        <em>const char *</em> <code>name</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Opens a named datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Topen</code> opens a named datatype at the location
        specified by <code>loc_id</code> and returns an identifier 
        for the datatype.  <code>loc_id</code> is either a file or 
        group identifier.  The identifier should eventually be closed 
        by calling <code>H5Tclose()</code> to release resources.    
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>loc_id</code>
            <dd>IN: A file or group identifier.
        <dt><em>const char *</em> <code>name</code>
            <dd>IN: A datatype name, defined within the file or group identified by <code>loc_id</code>.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a named datatype identifier if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5topen_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Commit">H5Tcommit</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em><code>H5Tcommit</code>(<em>hid_t</em> <code>loc_id</code>,
        <em>const char *</em> <code>name</code>,
        <em>hid_t</em> <code>type</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Commits a transient datatype to a file, creating a new named datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tcommit</code> commits a transient datatype 
        (not immutable) to a file, turned it into a named datatype.  
        The <code>loc_id</code> is either a file or group identifier  
        which, when combined with <code>name</code>, refers to a new 
        named datatype.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>loc_id</code>
            <dd>IN: A file or group identifier.
        <dt><em>const char *</em> <code>name</code>
            <dd>IN: A datatype name.
        <dt><em>hid_t</em> <code>type</code>
            <dd>IN: A datatype identifier.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tcommit_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Committed">H5Tcommitted</a>
<dt><strong>Signature:</strong>
    <dd><em>htri_t</em><code>H5Tcommitted</code>(<em>hid_t</em> <code>type</code>)
<dt><strong>Purpose:</strong>
    <dd>Determines whether a datatype is a named type or a transient type.  
<dt><strong>Description:</strong>
    <dd><code>H5Tcommitted</code> queries a type to determine whether 
        the type specified by the <code>type</code> identifier 
        is a named type or a transient type.  If this function returns 
        a positive value, then the type is named (that is, it has been 
        committed, perhaps by some other application).  Datasets which
        return committed datatypes with <code>H5Dget_type()</code> are 
        able to share the datatype with other datasets in the same file.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type</code>
            <dd>IN: Datatype identifier.
    </dl>
<dt><strong>Returns:</strong>
    <dd>When successful, returns a positive value, for <code>TRUE</code>, 
        if the datatype has been committed, or <code>0</code> (zero), 
        for <code>FALSE</code>, if the datatype has not been committed.
        Otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tcommitted_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Find">H5Tfind</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_conv_t</em> <code>H5Tfind</code>(<em>hid_t</em> <code>src_id</code>,
        <em>hid_t</em> <code>dst_id</code>,
        <em>H5T_cdata_t **</em><code>pcdata</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Finds a conversion function.
<dt><strong>Description:</strong>
    <dd><code>H5Tfind</code> finds a conversion function that can 
        handle a conversion from type <code>src_id</code> to type 
        <code>dst_id</code>.
        The <code>pcdata</code> argument is a pointer to a pointer 
        to type conversion data which was created and initialized 
        by the soft type conversion function of this path when the 
        conversion function was installed on the path.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>src_id</code>
            <dd>IN: Identifier for the source datatype.
        <dt><em>hid_t</em> <code>dst_id</code>
            <dd>IN: Identifier for the destination datatype.
        <dt><em>H5T_cdata_t **</em><code>pcdata</code>
            <dd>OUT: Pointer to type conversion data.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a pointer to a suitable conversion function if successful.
        Otherwise returns NULL.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tfind_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Convert">H5Tconvert</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tconvert</code>(<em>hid_t</em> <code>src_id</code>,
        <em>hid_t</em> <code>dst_id</code>,
        <em>hsize_t</em> <code>nelmts</code>,
        <em>void *</em><code>buf</code>,
        <em>void *</em><code>background</code>,
        <em>hid_t</em> <code>plist_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Converts data from between specified datatypes.
<dt><strong>Description:</strong>
    <dd><code>H5Tconvert</code> converts <code>nelmts</code> elements 
        from the type specified by the <code>src_id</code> identifier 
        to type <code>dst_id</code>.  
        The source elements are packed in <code>buf</code> and on return 
        the destination will be packed in <code>buf</code>.  
        That is, the conversion is performed in place.  
        The optional background buffer is an array of <code>nelmts</code> 
        values of destination type which are merged with the converted 
        values to fill in cracks (for instance, <code>background</code> 
        might be an array of structs with the <code>a</code> and 
        <code>b</code> fields already initialized and the conversion  
        of <code>buf</code> supplies the <code>c</code> and <code>d</code> 
        field values).
        <p>
        The parameter <code>plist_id</code> contains the dataset transfer 
        property list identifier which is passed to the conversion functions.  
        As of Release 1.2, this parameter is only used to pass along the 
        variable-length datatype custom allocation information.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>src_id</code>
            <dd>Identifier for the source datatype.
        <dt><em>hid_t</em> <code>dst_id</code>
            <dd>Identifier for the destination datatype.
        <dt><em>hsize_t</em> <code>nelmts</code>
            <dd>Size of array <code>buf</code>.
        <dt><em>void *</em><code>buf</code>
            <dd>Array containing pre- and post-conversion values.
        <dt><em>void *</em><code>background</code>
            <dd>Optional background buffer.
        <dt><em>hid_t</em> <code>plist_id</code>
            <dd>Dataset transfer property list identifier.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tconvert_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetOverflow">H5Tset_overflow</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tset_overflow</code>(<em>H5T_overflow_t</em> <code>func</code>)
<dt><strong>Purpose:</strong>
    <dd>Sets the overflow handler to a specified function. 
<dt><strong>Description:</strong>
    <dd><code>H5Tset_overflow</code> sets the overflow handler 
        to be the function specified by <code>func</code>.
        <code>func</code> will be called for all datatype conversions that 
        result in an overflow.  
        <p>
        See the definition of <code>H5T_overflow_t</code> in 
        <code>H5Tpublic.h</code> for documentation  
        of arguments and return values.  
        The prototype for <code>H5T_overflow_t</code> is as follows:<br>
              <code>herr_t (*H5T_overflow_t)(hid_t src_id, hid_t dst_id,
                                 void *src_buf, void *dst_buf);
              </code>
        <p>
        The NULL pointer may be passed to remove the overflow handler.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>H5T_overflow_t</em> <code>func</code>
            <dd>Overflow function.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_overflow_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetOverflow">H5Tget_overflow</a>
<dt><strong>Signature:</strong>


H5Tget_overflow ()
    <dd><em>H5T_overflow_t</em> <code>H5Tget_overflow</code>(<code>void</code>)
<dt><strong>Purpose:</strong>
    <dd>Returns a pointer to the current global overflow function.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_overflow</code> returns a pointer 
        to the current global overflow function.
        This is an application-defined function that is called whenever a 
        datatype conversion causes an overflow. 
<dt><strong>Parameters:</strong>
    <dl>
        <dt>None.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a pointer to an application-defined function if successful.
        Otherwise returns NULL; this can happen if no overflow handling
        function is registered.  
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_overflow_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Create">H5Tcreate</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t </em><code>H5Tcreate</code>(<em>H5T_class_t </em><code>class</code>,
        <em>size_t</em><code>size</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Creates a new datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tcreate</code> creates a new datatype of the specified 
        class with the specified number of bytes.  
        <p>
        The following datatype classes are supported with this function:
        <ul>
            <li><code>H5T_COMPOUND</code> 
            <li><code>H5T_OPAQUE</code> 
            <li><code>H5T_ENUM</code> 
        </ul>
        <p>
        Use <code>H5Tcopy</code> to create integer or floating-point datatypes. 
        <p>
        The datatype identifier returned from this function should be 
        released with <code>H5Tclose</code> or resource leaks will result.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>H5T_class_t</em> <code>class</code>
            <dd>Class of datatype to create.
        <dt><em>size_t</em> <code>size</code>
            <dd>The number of bytes in the datatype to create.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns datatype identifier if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tcreate_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-VLCreate">H5Tvlen_create</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t </em><code>H5Tvlen_create</code>(<em>hid_t </em><code>base_type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Creates a new variable-length datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tvlen_create</code> creates a new variable-length (VL) datatype.
        <p>
        The base datatype will be the datatype that the sequence is composed of,
        characters for character strings, vertex coordinates for polygon lists, etc.
        The base type specified for the VL datatype can be of any HDF5 datatype,
        including another VL datatype, a compound datatype or an atomic datatype.
        <p>
        When necessary, use <code>H5Tget_super</code> to determine the base type 
        of the VL datatype.
        <p>
        The datatype identifier returned from this function should be 
        released with <code>H5Tclose</code> or resource leaks will result.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>base_type_id</code>
            <dd>Base type of datatype to create.
    </dl>
<dt><strong>See Also:</strong>
    <dd><a href="RM_H5D.html#Dataset-GetVLBuf">H5Dget_vlen_buf_size</a>
    <dd><a href="RM_H5D.html#Dataset-VLReclaim">H5Dvlen_reclaim</a>
<dt><strong>Returns:</strong>
    <dd>Returns datatype identifier if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tvlen_create_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Copy">H5Tcopy</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t </em><code>H5Tcopy</code>(<em>hid_t </em><code>type_id</code>)
<dt><strong>Purpose:</strong>
    <dd>Copies an existing datatype.  
<dt><strong>Description:</strong>
    <dd><code>H5Tcopy</code> copies an existing datatype.  
        The returned type is always transient and unlocked.  
        <p>
        The <code>type_id</code> argument can be either a datatype
        identifier, a predefined datatype (defined in 
        <code>H5Tpublic.h</code>), or a dataset identifier.
        If <code>type_id</code> is a dataset identifier instead of a 
        datatype identifier, then this function returns a transient, 
        modifiable datatype which is a copy of the dataset's datatype.
        <p>
        The datatype identifier returned should be released with 
        <code>H5Tclose</code> or resource leaks will occur.  
<!--
        <p>
        Native datatypes supported by the library are:
        <ul> <dl>
            <dt>H5T_NATIVE_CHAR
                <dd> Native character type, declare dataset array as 'char'
            <dt>H5T_NATIVE_UCHAR
                <dd> Native unsigned character type, declare dataset array as 'unsigned char'
            <dt>H5T_NATIVE_SHORT
                <dd> Native short type, declare dataset array as 'short'
            <dt>H5T_NATIVE_USHORT
                <dd> Native unsigned short type, declare dataset array as 'unsigned short'
            <dt>H5T_NATIVE_INT
                <dd> Native int type, declare dataset array as 'int'
            <dt>H5T_NATIVE_UINT
                <dd> Native unsigned int type, declare dataset array as 'unsigned int'
            <dt>H5T_NATIVE_LONG
                <dd> Native long type, declare dataset array as 'unsigned long'
            <dt>H5T_NATIVE_ULONG
                <dd> Native unsigned long type, declare dataset array as 'unsigned long'
            <dt>H5T_NATIVE_LLONG
                <dd> Native long long type, declare dataset array as 'unsigned long long'
            <dt>H5T_NATIVE_ULLONG
                <dd> Native unsigned long long type, declare dataset array as 'unsigned long long'
            <dt>H5T_NATIVE_INT8
                <dd> Native signed 8-bit type, declare dataset array as 'int8'
            <dt>H5T_NATIVE_UINT8
                <dd> Native unsigned 8-bit type, declare dataset array as 'uint8'
            <dt>H5T_NATIVE_INT16
                <dd> Native signed 16-bit type, declare dataset array as 'int16'
            <dt>H5T_NATIVE_UINT16
                <dd> Native unsigned 16-bit type, declare dataset array as 'uint16'
            <dt>H5T_NATIVE_INT32
                <dd> Native signed 32-bit type, declare dataset array as 'int32'
            <dt>H5T_NATIVE_UINT32
                <dd> Native unsigned 32-bit type, declare dataset array as 'uint32'
            <dt>H5T_NATIVE_INT64
                <dd> Native signed 64-bit type, declare dataset array as 'uint64'
            <dt>H5T_NATIVE_UINT64
                <dd> Native unsigned 64-bit type, declare dataset array as 'uint64'
            <dt>H5T_NATIVE_FLOAT
                <dd> Native single-precision float type, declare dataset array as 'float'
            <dt>H5T_NATIVE_DOUBLE
                <dd> Native double-precision float type, declare dataset array as 'double'
            <dt>H5T_NATIVE_HSIZE
                <dd> Native size_t type, declare dataset array as 'hsize_t'
            <dt>H5T_NATIVE_HSSIZE
                <dd> Native signed size_t type, declare dataset array as 'hssize_t'
            <dt>H5T_NATIVE_HERR
                <dd> Native error type, declare dataset array as 'herr_t'
            <dt>H5T_NATIVE_HBOOL
                <dd> Native boolean type, declare dataset array as 'hbool_t'
        </dl> </ul>
-->
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to copy.  Can be a datatype
                identifier, a predefined datatype (defined in 
                <code>H5Tpublic.h</code>), or a dataset identifier.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a datatype identifier if successful;
        otherwise returns a negative value
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tcopy_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Equal">H5Tequal</a>
<dt><strong>Signature:</strong>
    <dd><em>htri_t </em><code>H5Tequal</code>(<em>hid_t </em><code>type_id1</code>,
        <em>hid_t</em><code>type_id2</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Determines whether two datatype identifiers refer to the same datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tequal</code> determines whether two datatype identifiers 
        refer to the same datatype.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id1</code>
            <dd>Identifier of datatype to compare.
        <dt><em>hid_t</em> <code>type_id2</code>
            <dd>Identifier of datatype to compare.
    </dl>
<dt><strong>Returns:</strong>
    <dd>When successful, returns a positive value, for <code>TRUE</code>, 
        if the datatype identifiers refer to the same datatype, 
        or <code>0</code> (zero), for <code>FALSE</code>.
        Otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tequal_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Lock">H5Tlock</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tlock</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Locks a datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tlock</code> locks the datatype specified by the 
        <code>type_id</code> identifier, making it read-only and 
        non-destructible.  This is normally done by the library for 
        predefined datatypes so the application does not 
        inadvertently change or delete a predefined type.  
        Once a datatype is locked it can never be unlocked.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to lock.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tlock_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetClass">H5Tget_class</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_class_t </em><code>H5Tget_class</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the datatype class identifier.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_class</code> returns the datatype class identifier.
        <p>
        Valid class identifiers, as defined in <code>H5Tpublic.h</code>, are:
        <ul><li><code>H5T_INTEGER</code>
            <li><code>H5T_FLOAT</code>
            <li><code>H5T_TIME</code>
            <li><code>H5T_STRING</code>
            <li><code>H5T_BITFIELD</code>
            <li><code>H5T_OPAQUE</code>
            <li><code>H5T_COMPOUND</code>
            <li><code>H5T_REFERENCE</code>
            <li><code>H5T_ENUM</code>
            <li><code>H5T_VLEN</code>
            <li><code>H5T_ARRAY</code>
        </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns datatype class identifier if successful;
        otherwise <code>H5T_NO_CLASS</code> (-1).
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_class_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetSize">H5Tget_size</a>
<dt><strong>Signature:</strong>
    <dd><em>size_t </em><code>H5Tget_size</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the size of a datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_size</code> returns the size of a datatype in bytes.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the size of the datatype in bytes if successful;
        otherwise 0.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_size_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetSize">H5Tset_size</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_size</code>(<em>hid_t </em><code>type_id</code>,
        <em>size_t</em><code>size</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the total size for an atomic datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_size</code> sets the total size in bytes, 
        <code>size</code>, for an atomic datatype (this operation
        is not permitted on compound datatypes).  If the size is
         decreased so that the significant bits of the datatype extend beyond
         the edge of the new size, then the `offset' property is decreased
         toward zero.  If the `offset' becomes zero and the significant
         bits of the datatype still hang over the edge of the new size, then
         the number of significant bits is decreased.
         Adjusting the size of an H5T_STRING automatically sets the precision
         to 8*size.  All datatypes have a positive size.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to change size.
        <dt><em>size_t</em> <code>size</code>
            <dd>Size in bytes to modify datatype.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_size_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetSuper">H5Tget_super</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t</em> <code>H5Tget_super</code>(<em>hid_t</em> <code>type</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the base datatype from which a datatype is derived.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_super</code> returns the base datatype from which the 
        datatype <code>type</code> is derived.  
        <P>
        In the case of an enumeration type, the return value is an integer type.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type</code>
            <dd>Datatype identifier for the derived datatype.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the datatype identifier for the base datatype if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_super_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetOrder">H5Tget_order</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_order_t </em><code>H5Tget_order</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the byte order of an atomic datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_order</code> returns the byte order of an 
        atomic datatype.
        <p>
        Possible return values are:
        <ul><dl>
            <dt><code>H5T_ORDER_LE</code> (<code>0</code>)
                <dd>Little endian byte ordering (default).
            <dt><code>H5T_ORDER_BE</code> (<code>1</code>)
                <dd>Big endian byte ordering.
            <dt><code>H5T_ORDER_VAX</code> (<code>2</code>)
                <dd>VAX mixed byte ordering (not currently supported).
        </dl></ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a byte order constant if successful;
        otherwise <code>H5T_ORDER_ERROR</code> (-1).
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_order_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetOrder">H5Tset_order</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_order</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_order_t</em><code>order</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the byte ordering of an atomic datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_order</code> sets the byte ordering of an atomic datatype.
        Byte orderings currently supported are:
        <ul> <dl>
            <dt>H5T_ORDER_LE (<code>0</code>)
                <dd> Little-endian byte ordering (default).
            <dt>H5T_ORDER_BE (<code>1</code>)
                <dd> Big-endian byte ordering.
            <dt>H5T_ORDER_VAX (<code>2</code>)
                <dd>VAX mixed byte ordering (not currently supported).
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>H5T_order_t</em> <code>order</code>
            <dd>Byte ordering constant.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_order_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetPrecision">H5Tget_precision</a>
<dt><strong>Signature:</strong>
    <dd><em>size_t </em><code>H5Tget_precision</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the precision of an atomic datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_precision</code> returns the precision of an atomic datatype.  The
        precision is the number of significant bits which, unless padding is
        present, is 8 times larger than the value returned by H5Tget_size().
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the number of significant bits if successful;
        otherwise 0.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_precision_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetPrecision">H5Tset_precision</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_precision</code>(<em>hid_t </em><code>type_id</code>,
        <em>size_t</em><code>precision</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the precision of an atomic datatype.  
<dt><strong>Description:</strong>
    <dd><code>H5Tset_precision</code> sets the precision of an atomic datatype.  
        The precision is the number of significant bits which, unless padding 
        is present, is 8 times larger than the value returned by H5Tget_size().
        <P>If the precision is increased then the offset is decreased and then
            the size is increased to insure that significant bits do not "hang
            over" the edge of the datatype.
        <P>Changing the precision of an H5T_STRING automatically changes the
            size as well.  The precision must be a multiple of 8.
        <P>When decreasing the precision of a floating point type, set the
            locations and sizes of the sign, mantissa, and exponent fields
            first.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>size_t</em> <code>precision</code>
            <dd>Number of bits of precision for datatype.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_precision_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetOffset">H5Tget_offset</a>
<dt><strong>Signature:</strong>
    <dd><em>int </em><code>H5Tget_offset</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the bit offset of the first significant bit.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_offset</code> retrieves the bit offset of the first significant bit.
        The significant bits of an atomic datum can be offset from the beginning
        of the memory for that datum by an amount of padding. The `offset'
        property specifies the number of bits of padding that appear to the
        "right of" the value.  That is, if we have a 32-bit datum with 16-bits
        of precision having the value 0x1122 then it will be laid out in
        memory as (from small byte address toward larger byte addresses):
        <br>
        <br>

      <table border align=center cellpadding=4 width="80%">
        <tr align=center>
          <th width="20%">Byte Position</th>
          <th width="20%">Big-Endian Offset=0</th>
          <th width="20%">Big-Endian Offset=16</th>
          <th width="20%">Little-Endian Offset=0</th>
          <th width="20%">Little-Endian Offset=16</th>
        </tr>  
        <tr align=center>
          <td>0:</td>
          <td>[ pad]</td>
          <td>[0x11]</td>
          <td>[0x22]</td>
          <td>[ pad]</td>
        </tr>
        <tr align=center>
          <td>1:</td>
          <td>[ pad]</td>
          <td>[0x22]</td>
          <td>[0x11]</td>
          <td>[ pad]</td>
        </tr>
        <tr align=center>
          <td>2:</td>
          <td>[0x11]</td>
          <td>[ pad]</td>
          <td>[ pad]</td>
          <td>[0x22]</td>
        </tr>
        <tr align=center>
          <td>3:</td>
          <td>[0x22]</td>
          <td>[ pad]</td>
          <td>[ pad]</td>
          <td>[0x11]</td>
        </tr>
      </table>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns an offset value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_offset_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetOffset">H5Tset_offset</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_offset</code>(<em>hid_t </em><code>type_id</code>,
        <em>size_t</em> <code>offset</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the bit offset of the first significant bit.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_offset</code> sets the bit offset of the first significant bit.  The
        significant bits of an atomic datum can be offset from the beginning of
        the memory for that datum by an amount of padding. The `offset'
        property specifies the number of bits of padding that appear to the
        "right of" the value.  That is, if we have a 32-bit datum with 16-bits
        of precision having the value 0x1122 then it will be laid out in
        memory as (from small byte address toward larger byte addresses):
        <br>
        <br>

      <table border align=center cellpadding=4 width="80%">
        <tr align=center>
          <th width="20%">Byte Position</th>
          <th width="20%">Big-Endian Offset=0</th>
          <th width="20%">Big-Endian Offset=16</th>
          <th width="20%">Little-Endian Offset=0</th>
          <th width="20%">Little-Endian Offset=16</th>
        </tr>  
        <tr align=center>
          <td>0:</td>
          <td>[ pad]</td>
          <td>[0x11]</td>
          <td>[0x22]</td>
          <td>[ pad]</td>
        </tr>
        <tr align=center>
          <td>1:</td>
          <td>[ pad]</td>
          <td>[0x22]</td>
          <td>[0x11]</td>
          <td>[ pad]</td>
        </tr>
        <tr align=center>
          <td>2:</td>
          <td>[0x11]</td>
          <td>[ pad]</td>
          <td>[ pad]</td>
          <td>[0x22]</td>
        </tr>
        <tr align=center>
          <td>3:</td>
          <td>[0x22]</td>
          <td>[ pad]</td>
          <td>[ pad]</td>
          <td>[0x11]</td>
        </tr>
      </table>

<P>If the offset is incremented then the total size is
incremented also if necessary to prevent significant bits of
the value from hanging over the edge of the datatype.

<P>The offset of an H5T_STRING cannot be set to anything but
zero.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>size_t</em> <code>offset</code>
            <dd>Offset of first significant bit.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_offset_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetPad">H5Tget_pad</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tget_pad</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_pad_t *</em> <code>lsb</code>,
        <em>H5T_pad_t *</em> <code>msb</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the padding type of the least and most-significant bit padding.  
<dt><strong>Description:</strong>
    <dd><code>H5Tget_pad</code> retrieves the padding type of the least and most-significant
        bit padding.  Valid types are:
        <ul> <dl>
            <dt>H5T_PAD_ZERO (<code>0</code>)
               <dd>Set background to zeros.
            <dt>H5T_PAD_ONE (<code>1</code>)
               <dd>Set background to ones.
            <dt>H5T_PAD_BACKGROUND (<code>2</code>)
               <dd>Leave background alone.
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>IN: Identifier of datatype to query.
        <dt><em>H5T_pad_t *</em> <code>lsb</code>
            <dd>OUT: Pointer to location to return least-significant 
                bit padding type.
        <dt><em>H5T_pad_t *</em> <code>msb</code>
            <dd>OUT: Pointer to location to return most-significant 
                bit padding type.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_pad_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetPad">H5Tset_pad</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_pad</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_pad_t</em> <code>lsb</code>,
        <em>H5T_pad_t</em> <code>msb</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the least and most-significant bits padding types.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_pad</code> sets the least and most-significant bits padding types.
        <ul> <dl>
            <dt>H5T_PAD_ZERO (<code>0</code>)
               <dd>Set background to zeros.
            <dt>H5T_PAD_ONE (<code>1</code>)
               <dd>Set background to ones.
            <dt>H5T_PAD_BACKGROUND (<code>2</code>)
               <dd>Leave background alone.
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>H5T_pad_t</em> <code>lsb</code>
            <dd>Padding type for least-significant bits.
        <dt><em>H5T_pad_t</em> <code>msb</code>
            <dd>Padding type for most-significant bits.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_pad_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetSign">H5Tget_sign</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_sign_t </em><code>H5Tget_sign</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the sign type for an integer type.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_sign</code> retrieves the sign type for an integer type.
        Valid types are:
        <ul> <dl>
            <dt>H5T_SGN_NONE (<code>0</code>)
               <dd>Unsigned integer type.
            <dt>H5T_SGN_2 (<code>1</code>)
               <dd>Two's complement signed integer type.
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a valid sign type if successful;
        otherwise <code>H5T_SGN_ERROR</code> (-1).
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_sign_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetSign">H5Tset_sign</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_sign</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_sign_t</em> <code>sign</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the sign property for an integer type.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_sign</code> sets the sign property for an integer type.
        <ul> <dl>
            <dt>H5T_SGN_NONE (<code>0</code>)
               <dd>Unsigned integer type.
            <dt>H5T_SGN_2 (<code>1</code>)
               <dd>Two's complement signed integer type.
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>H5T_sign_t</em> <code>sign</code>
            <dd>Sign type.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_sign_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetFields">H5Tget_fields</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tget_fields</code>(<em>hid_t </em><code>type_id</code>,
        <em>size_t *</em><code>spos</code>,
        <em>size_t *</em><code>epos</code>,
        <em>size_t *</em><code>esize</code>,
        <em>size_t *</em><code>mpos</code>,
        <em>size_t *</em><code>msize</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves floating point datatype bit field information.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_fields</code> retrieves information about the locations of the various
        bit fields of a floating point datatype.  The field positions are bit
        positions in the significant region of the datatype.  Bits are
        numbered with the least significant bit number zero.
        Any (or even all) of the arguments can be null pointers.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>IN: Identifier of datatype to query.
        <dt><em>size_t *</em><code>spos</code>
            <dd>OUT: Pointer to location to return floating-point sign bit.
        <dt><em>size_t *</em><code>epos</code>
            <dd>OUT: Pointer to location to return exponent bit-position.
        <dt><em>size_t *</em><code>esize</code>
            <dd>OUT: Pointer to location to return size of exponent in bits.
        <dt><em>size_t *</em><code>mpos</code>
            <dd>OUT: Pointer to location to return mantissa bit-position.
        <dt><em>size_t *</em><code>msize</code>
            <dd>OUT: Pointer to location to return size of mantissa in bits.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_fields_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetFields">H5Tset_fields</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_fields</code>(<em>hid_t </em><code>type_id</code>,
        <em>size_t</em> <code>spos</code>,
        <em>size_t</em> <code>epos</code>,
        <em>size_t</em> <code>esize</code>,
        <em>size_t</em> <code>mpos</code>,
        <em>size_t</em> <code>msize</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets locations and sizes of floating point bit fields.  
<dt><strong>Description:</strong>
    <dd><code>H5Tset_fields</code> sets the locations and sizes of the various
        floating-point bit fields.  The field positions are bit positions in the
        significant region of the datatype.  Bits are numbered with the least
        significant bit number zero.
    
        <P>Fields are not allowed to extend beyond the number of bits of
        precision, nor are they allowed to overlap with one another.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>size_t</em> <code>spos</code>
            <dd>Sign position, i.e., the bit offset of the floating-point 
                sign bit.
        <dt><em>size_t</em> <code>epos</code>
            <dd>Exponent bit position.
        <dt><em>size_t</em> <code>esize</code>
            <dd>Size of exponent in bits.
        <dt><em>size_t</em> <code>mpos</code>
            <dd>Mantissa bit position.
        <dt><em>size_t</em> <code>msize</code>
            <dd>Size of mantissa in bits.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_fields_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetEbias">H5Tget_ebias</a>
<dt><strong>Signature:</strong>
    <dd><em>size_t </em><code>H5Tget_ebias</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the exponent bias of a floating-point type.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_ebias</code> retrieves the exponent bias of a floating-point type.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the bias if successful;
        otherwise 0.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_ebiass_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetEbias">H5Tset_ebias</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_ebias</code>(<em>hid_t </em><code>type_id</code>,
        <em>size_t</em> <code>ebias</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the exponent bias of a floating-point type.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_ebias</code> sets the exponent bias of a floating-point type.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>size_t</em> <code>ebias</code>
            <dd>Exponent bias value.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_ebiass_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetNorm">H5Tget_norm</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_norm_t </em><code>H5Tget_norm</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves mantissa normalization of a floating-point datatype.  
<dt><strong>Description:</strong>
    <dd><code>H5Tget_norm</code> retrieves the mantissa normalization of 
        a floating-point datatype.  Valid normalization types are:
        <ul> <dl>
            <dt>H5T_NORM_IMPLIED (<code>0</code>)
                <dd>MSB of mantissa is not stored, always 1
            <dt>H5T_NORM_MSBSET (<code>1</code>)
                <dd>MSB of mantissa is always 1
            <dt>H5T_NORM_NONE (<code>2</code>)
                <dd>Mantissa is not normalized
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a valid normalization type if successful;
        otherwise <code>H5T_NORM_ERROR</code> (-1).
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_norm_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetNorm">H5Tset_norm</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_norm</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_norm_t</em> <code>norm</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets the mantissa normalization of a floating-point datatype.  
<dt><strong>Description:</strong>
    <dd><code>H5Tset_norm</code> sets the mantissa normalization of 
        a floating-point datatype.  Valid normalization types are:
        <ul> <dl>
            <dt>H5T_NORM_IMPLIED (<code>0</code>)
                <dd>MSB of mantissa is not stored, always 1
            <dt>H5T_NORM_MSBSET (<code>1</code>)
                <dd>MSB of mantissa is always 1
            <dt>H5T_NORM_NONE (<code>2</code>)
                <dd>Mantissa is not normalized
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to set.
        <dt><em>H5T_norm_t</em> <code>norm</code>
            <dd>Mantissa normalization type.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_norm_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetInpad">H5Tget_inpad</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_pad_t </em><code>H5Tget_inpad</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the internal padding type for unused bits in floating-point datatypes.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_inpad</code> retrieves the internal padding type for 
        unused bits in floating-point datatypes.
        Valid padding types are:
        <ul> <dl>
            <dt>H5T_PAD_ZERO (<code>0</code>)
               <dd>Set background to zeros.
            <dt>H5T_PAD_ONE (<code>1</code>)
               <dd>Set background to ones.
            <dt>H5T_PAD_BACKGROUND (<code>2</code>)
               <dd>Leave background alone.
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a valid padding type if successful;
        otherwise <code>H5T_PAD_ERROR</code> (-1).
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_inpad_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetInpad">H5Tset_inpad</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_inpad</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_pad_t</em> <code>inpad</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Fills unused internal floating point bits.
<dt><strong>Description:</strong>
    <dd>If any internal bits of a floating point type are unused
        (that is, those significant bits which are not part of the
        sign, exponent, or mantissa), then <code>H5Tset_inpad</code> will be filled
        according to the value of the padding value property <code>inpad</code>.
        Valid padding types are:
        <ul> <dl>
            <dt>H5T_PAD_ZERO (<code>0</code>)
               <dd>Set background to zeros.
            <dt>H5T_PAD_ONE (<code>1</code>)
               <dd>Set background to ones.
            <dt>H5T_PAD_BACKGROUND (<code>2</code>)
               <dd>Leave background alone.
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to modify.
        <dt><em>H5T_pad_t</em> <code>pad</code>
            <dd>Padding type.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_inpad_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetCset">H5Tget_cset</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_cset_t </em><code>H5Tget_cset</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the character set type of a string datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_cset</code> retrieves the character set type 
        of a string datatype.  Valid character set types are:
        <ul> <dl>
            <dt>H5T_CSET_ASCII (<code>0</code>)
               <dd>Character set is US ASCII
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a valid character set type if successful;
        otherwise <code>H5T_CSET_ERROR</code> (-1).
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_cset_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetCset">H5Tset_cset</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_cset</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_cset_t</em> <code>cset</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Sets character set to be used.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_cset</code> the character set to be used.
        <p>
        HDF5 is able to distinguish between character sets of different
        nationalities and to convert between them to the extent possible.
        Valid character set types are:
        <ul> <dl>
            <dt>H5T_CSET_ASCII (<code>0</code>)
               <dd>Character set is US ASCII.
        </dl> </ul>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to modify.
        <dt><em>H5T_cset_t</em> <code>cset</code>
            <dd>Character set type.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_cset_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetStrpad">H5Tget_strpad</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_str_t </em><code>H5Tget_strpad</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the storage mechanism for a string datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_strpad</code> retrieves the storage mechanism
        for a string datatype, as defined in 
        <a href="#Datatype-SetStrpad"><code>H5Tset_strpad</code></a>.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a valid string storage mechanism if successful;
        otherwise <code>H5T_STR_ERROR</code> (-1).
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_strpad_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetStrpad">H5Tset_strpad</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tset_strpad</code>(<em>hid_t </em><code>type_id</code>,
        <em>H5T_str_t</em> <code>strpad</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Defines the storage mechanism for character strings.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_strpad</code> defines the storage mechanism for the string.
        <p>
        The method used to store character strings differs with the 
        programming language: 
        <ul>
            <li>C usually null terminates strings while 
            <li>Fortran left-justifies and space-pads strings.
        </ul>
        Valid string padding values, as passed in the parameter 
        <code>strpad</code>, are as follows:
        <ul> <dl>
            <dt>H5T_STR_NULLTERM (<code>0</code>)
               <dd>Null terminate (as C does)
            <dt>H5T_STR_NULLPAD (<code>1</code>)
               <dd>Pad with zeros 
            <dt>H5T_STR_SPACEPAD (<code>2</code>)
               <dd>Pad with spaces (as FORTRAN does)
        </dl> </ul>
        <p>
        When converting from a longer string to a shorter string,
        the behavior is as follows.
        If the short string is <code>H5T_STR_NULLPAD</code> or 
        <code>H5T_STR_SPACEPAD</code>, then the string is simply truncated. 
        If the short string is <code>H5T_STR_NULLTERM</code>, it is
        truncated and a null terminator is appended.  
        <p>
        When converting from a shorter string to a longer string,
        the long string is padded on the end by appending nulls or spaces.


<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to modify.
        <dt><em>H5T_str_t</em> <code>strpad</code>
            <dd>String padding type.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_strpad_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetNmembers">H5Tget_nmembers</a>
<dt><strong>Signature:</strong>
    <dd><em>int </em><code>H5Tget_nmembers</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the number of elements in a compound or enumeration datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_nmembers</code> retrieves 
        the number of fields in a compound datatype or 
        the number of members of an enumeration datatype.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the number of elements if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_nmembers_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetMemberClass">H5Tget_member_class</a>
<dt><strong>Signature:</strong>
    <dd><em>H5T_class_t</em> <code>H5Tget_member_class</code>(
                       <em>hid_t</em> <code>cdtype_id</code>,
                       <em>int </em><code>member_no</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns datatype class of compound datatype member.
<dt><strong>Description:</strong>
    <dd>Given a compound datatype, <code>cdtype_id</code>, the function 
        <code>H5Tget_member_class</code> returns the datatype class of 
        the compound datatype member specified by <code>member_no</code>.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>cdtype_id</code>
            <dd>IN: Datatype identifier of compound object.
        <dt><em>int</em> <code>member_no</code>
            <dd>IN: Compound object member number.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the datatype class, a non-negative value, if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5txxx_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetMemberName">H5Tget_member_name</a>
<dt><strong>Signature:</strong>
    <dd><em>char *</em> <code>H5Tget_member_name</code>(<em>hid_t </em><code>type_id</code>,
        <em>int</em> <code>field_idx</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the name of a compound or enumeration datatype member.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_member_name</code> retrieves the name of a field 
        of a compound datatype or an element of an enumeration datatype.  
        <p>
        The index of the target field or element is specified in
        <code>field_idx</code>.
        Compound datatype fields and enumeration datatype elements 
        are stored in no particular order
        with index values of 0 through <em>N</em>-1, where <em>N</em> 
        is the value returned by <code>H5Tget_nmembers</code>.  
        <p>
        A buffer to receive the name of the field is 
        allocated with <code>malloc()</code> and the caller is responsible 
        for freeing the memory used.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
        <dt><em>int</em> <code>field_idx</code>
            <dd>Zero-based index of the field or element whose name
                is to be retrieved.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a valid pointer to a string allocated with 
        <code>malloc()</code> if successful; 
        otherwise returns NULL.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_member_name_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetMemberIndex">H5Tget_member_index</a>
<dt><strong>Signature:</strong>
    <dd><em>int</em> <code>H5Tget_member_index</code>(<em>hid_t </em><code>type_id</code>,
        <em>const char *</em> <code>field_name</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the index of a compound or enumeration datatype member.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_member_index</code> retrieves the index of a field 
        of a compound datatype or an element of an enumeration datatype.  
        <p>
        The name of the target field or element is specified in
        <code>field_name</code>.
        <p>
        Fields are stored in no particular order 
        with index values of 0 through <em>N</em>-1, where <em>N</em> is 
        the value returned by <code>H5Tget_nmembers</code>.  
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
        <dt><em>const char *</em> <code>field_name</code>
            <dd>Name of the field or member whose index is to be retrieved.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a valid field or member index if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_member_index_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetMemberOffset">H5Tget_member_offset</a>
<dt><strong>Signature:</strong>
    <dd><em>size_t</em> <code>H5Tget_member_offset</code>(<em>hid_t </em><code>type_id</code>,
        <em>int</em> <code>memb_no</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Retrieves the offset of a field of a compound datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_member_offset</code> retrieves the 
        byte offset of the beginning of a field within a 
        compound datatype with respect to the beginning 
        of the compound data type datum. 
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
        <dt><em>int</em> <code>memb_no</code>
            <dd>Number of the field whose offset is requested.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the byte offset of the field if successful;
        otherwise returns <code>0</code> (zero).
        Note that zero is a valid offset and that this function 
        will fail only if a call to <code>H5Tget_member_class()</code> 
        fails with the same arguments.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_member_offset_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetMemberType">H5Tget_member_type</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t</em> <code>H5Tget_member_type</code>(<em>hid_t </em><code>type_id</code>,
        <em>int</em> <code>field_idx</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the datatype of the specified member.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_member_type</code> returns the datatype of the specified member.  The caller
        should invoke H5Tclose() to release resources associated with the type.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to query.
        <dt><em>int</em> <code>field_idx</code>
            <dd>Field index (0-based) of the field type to retrieve.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the identifier of a copy of the datatype of the field
        if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_member_type_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Insert">H5Tinsert</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tinsert</code>(<em>hid_t </em><code>type_id</code>,
        <em>const char *</em> <code>name</code>,
        <em>size_t</em> <code>offset</code>,
        <em>hid_t</em> <code>field_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Adds a new member to a compound datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tinsert</code> adds another member to the compound datatype
        <code>type_id</code>.  The new member has a <code>name</code> which
        must be unique within the compound datatype. 
        The <code>offset</code> argument defines the start of the member 
        in an instance of the compound datatype, and <code>field_id</code> 
        is the datatype identifier of the new member.
        <P>
        Note: Members of a compound datatype do not have to be atomic datatypes; 
        a compound datatype can have a member which is a compound datatype.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of compound datatype to modify.
        <dt><em>const char *</em> <code>name</code>
            <dd>Name of the field to insert.
        <dt><em>size_t</em> <code>offset</code>
            <dd>Offset in memory structure of the field to insert.
        <dt><em>hid_t</em> <code>field_id</code>
            <dd>Datatype identifier of the field to insert.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tinsert_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Pack">H5Tpack</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tpack</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Recursively removes padding from within a compound datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tpack</code> recursively removes padding from within a compound
        datatype to make it more efficient (space-wise) to store that data.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to modify.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tpack_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Register">H5Tregister</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tregister</code>(<em>H5T_pers_t</em> <code>pers</code>, 
        <em>const char *</em> <code>name</code>, 
        <em>hid_t </em><code>src_id</code>,
        <em>hid_t</em> <code>dst_id</code>,
        <em>H5T_conv_t</em> <code>func</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Registers a conversion function.
<dt><strong>Description:</strong>
    <dd><code>H5Tregister</code> registers a hard or soft conversion function 
        for a datatype conversion path.  
        <p>
        The parameter <code>pers</code> indicates whether a conversion function 
        is <em>hard</em> (<code>H5T_PERS_HARD</code>) 
        or <em>soft</em> (<code>H5T_PERS_SOFT</code>).
        <p>
        A conversion path can have only one hard function.
        When <code>pers</code> is <code>H5T_PERS_HARD</code>, 
        <code>func</code> replaces any previous hard function.
        If  <code>pers</code> is <code>H5T_PERS_HARD</code> and 
        <code>func</code> is the null pointer, then any hard function 
        registered for this path is removed.  
        <p>
        When <code>pers</code> is <code>H5T_PERS_SOFT</code>, 
        <code>H5Tregister</code> 
        adds the function to the end of the master soft list and replaces 
        the soft function in all applicable existing conversion paths. 
        Soft functions are used when determining which conversion function 
        is appropriate for this path.  
        <p>
        The <code>name</code> is used only for debugging and should be a 
        short identifier for the function.  
        <p>
        The path is specified by the source and destination datatypes 
        <code>src_id</code> and <code>dst_id</code>.  
        For soft conversion functions, only the class of these types is important.
        <p>
        The type of the conversion function pointer is declared as:
        <dir>
<pre><code>typedef</code> <em>herr_t </em>(<code>*H5T_conv_t</code>) (<em>hid_t </em><code>src_id</code>, 
                              <em>hid_t </em><code>dst_id</code>, 
                              <em>H5T_cdata_t *</em><code>cdata</code>,
                              <em>hsize_t </em><code>nelmts</code>, 
                              <em>size_t </em><code>buf_stride</code>, 
                              <em>size_t </em><code>bkg_stride</code>, 
                              <em>void *</em><code>buf</code>, 
                              <em>void *</em><code>bkg</code>,
                              <em>hid_t </em><code>dset_xfer_plist</code>)</pre>
        </dir>
        <p>
        The <code>H5T_cdata_t</code> struct is declared as:
        <dir>
<pre><code>typedef</code> <em>struct </em><code>*H5T_cdata_t</code> (<em>H5T_cmd_t </em><code>command</code>, 
                             <em>H5T_bkg_t </em><code>need_bkg</code>, 
                             <em>hbool_t *</em><code>recalc</code>,
                             <em>void *</em><code>priv</code>)</pre>
        </dir>
        <p>
        The <code>H5T_conv_t</code> parameters and 
        the elements of the <code>H5T_cdata_t</code> struct
        are described more fully in the 
        &ldquo;<a href="Datatypes.html#Datatypes-DataConversion" 
        target="WinUG">Data Conversion</a>&rdquo; 
        section of&nbsp; &ldquo;The Datatype Interface (H5T)&rdquo; 
        in the <cite>HDF5 User's Guide</cite>.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>H5T_pers_t</em> <code>pers</code>
            <dd><code>H5T_PERS_HARD</code> for hard conversion functions;
                <code>H5T_PERS_SOFT</code> for soft conversion functions.
        <dt><em>const char *</em> <code>name</code>
            <dd>Name displayed in diagnostic output.
        <dt><em>hid_t</em> <code>src_id</code>
            <dd>Identifier of source datatype.
        <dt><em>hid_t</em> <code>dst_id</code>
            <dd>Identifier of destination datatype.
        <dt><em>H5T_conv_t</em> <code>func</code>
            <dd>Function to convert between source and destination datatypes.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tregister_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Unregister">H5Tunregister</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tunregister</code>(<em>H5T_conv_t</em> <code>func</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Removes a conversion function from all conversion paths.
<dt><strong>Description:</strong>
    <dd><code>H5Tunregister</code> removes a conversion function from all conversion paths.
        <P>
        The conversion function pointer type declaration is described in 
        <a href="#Datatype-Register">H5Tregister</a>.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>H5T_conv_t</em> <code>func</code>
            <dd>Function to remove from conversion paths.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tunregister_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->     <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-EnumCreate">H5Tenum_create</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t</em> <code>H5Tenum_create</code>(<em>hid_t</em> <code>parent_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Creates a new enumeration datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tenum_create</code> creates a new enumeration datatype 
        based on the specified base datatype, <code>parent_id</code>, 
        which must be an integer type.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>parent_id</code>
            <dd>IN: Datatype identifier for the base datatype.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the datatype identifier for the new enumeration datatype if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tenum_create_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-EnumInsert">H5Tenum_insert</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tenum_insert</code>(<em>hid_t</em> <code>type</code>,
        <em>const char</em> *<code>name</code>,
        <em>void</em> *<code>value</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Inserts a new enumeration datatype member.
<dt><strong>Description:</strong>
    <dd><code>H5Tenum_insert</code> inserts a 
        new enumeration datatype member into an enumeration datatype. 
        <p>
        <code>type</code> is the enumeration datatype, 
        <code>name</code> is the name of the new member, and 
        <code>value</code> points to the value of the new member.
        <p>
        <code>name</code> and <code>value</code> must both 
        be unique within <code>type</code>. 
        <p>
        <code>value</code> points to data which is of the 
        datatype defined when the enumeration datatype was created.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type</code>
            <dd>IN: Datatype identifier for the enumeration datatype.
        <dt><em>const char</em> *<code>name</code>
            <dd>IN: Name of the new member.
        <dt><em>void</em> *<code>value</code>
            <dd>IN: Pointer to the value of the new member.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tenum_insert_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-EnumNameOf">H5Tenum_nameof</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tenum_nameof</code>(<em>hid_t</em> <code>type</code>
        <em>void</em> *<code>value</code>,
        <em>char</em> *<code>name</code>,
        <em>size_t</em> <code>size</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the symbol name corresponding to a specified member of an enumeration datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tenum_nameof</code> finds the symbol name that 
        corresponds to the specified <code>value</code>
        of the enumeration datatype <code>type</code>. 
        <p>
        At most <code>size</code> characters of the symbol 
        name are copied into the <code>name</code> buffer. 
        If the entire symbol name and null terminator 
        do not fit in the <code>name</code> buffer, then as 
        many characters as possible are copied 
        (not null terminated) and the function fails.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type</code>
            <dd>IN: Enumeration datatype identifier.
        <dt><em>void</em> *<code>value</code>,
            <dd>IN: Value of the enumeration datatype.
        <dt><em>char</em> *<code>name</code>,
            <dd>OUT: Buffer for output of the symbol name.
        <dt><em>size_t</em> <code>size</code>
            <dd>IN: Anticipated size of the symbol name, in bytes (characters).
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful.
        Otherwise returns a negative value 
        and, if <code>size</code> allows it, 
        the first character of <code>name</code> is 
        set to <code>NULL</code>.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tenum_nameof_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-EnumValueOf">H5Tenum_valueof</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tenum_valueof</code>(<em>hid_t</em> <code>type</code>
        <em>char</em> *<code>name</code>,
        <em>void</em> *<code>value</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the value corresponding to a specified member of an enumeration datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tenum_valueof</code> finds the value that
        corresponds to the specified <code>name</code>
        of the enumeration datatype <code>type</code>. 
        <p>
        The <code>value</code> argument should be at least
        as large as the value of <code>H5Tget_size(type)</code>
        in order to hold the result.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type</code>
            <dd>IN: Enumeration datatype identifier.
        <dt><em>const char</em> *<code>name</code>,
            <dd>IN: Symbol name of the enumeration datatype.
        <dt><em>void</em> *<code>value</code>,
            <dd>OUT: Buffer for output of the value of the enumeration datatype.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tenum_valueof_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetMemberValue">H5Tget_member_value</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t</em> <code>H5Tget_member_value</code>(<em>hid_t</em> <code>type</code>
        <em>int</em> <code>memb_no</code>,
        <em>void</em> *<code>value</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the value of an enumeration datatype member.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_member_value</code> returns the value of 
        the enumeration datatype member <code>memb_no</code>.
        <p>
        The member value is returned in a user-supplied buffer 
        pointed to by <code>value</code>.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type</code>
            <dd>IN: Datatype identifier for the enumeration datatype.
        <dt><em>int</em> <code>memb_no</code>,
            <dd>IN: Number of the enumeration datatype member.
        <dt><em>void</em> *<code>value</code>
            <dd>OUT: Pointer to a buffer for output of the 
                value of the enumeration datatype member.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_member_value_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-SetTag">H5Tset_tag</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tset_tag</code>(<em>hid_t</em> <code>type_id</code>
        <em>const char</em> *<code>tag</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Tags an opaque datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tset_tag</code> tags an opaque datatype <code>type_id</code>
        with a descriptive ASCII identifier,<code> tag</code>.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>IN: Datatype identifier for the opaque datatype to be tagged.
        <dt><em>const char</em> *<code>tag</code>
            <dd>IN: Descriptive ASCII string with which the 
                opaque datatype is to be tagged.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tset_tag_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetTag">H5Tget_tag</a>
<dt><strong>Signature:</strong>
    <dd><em>char</em> *<code>H5Tget_tag</code>(<em>hid_t</em> <code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Gets the tag associated with an opaque datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_tag</code> returns the tag associated with 
        the opaque datatype <code>type_id</code>.
        <P>
        The tag is returned via a pointer to an 
        allocated string, which the caller must free.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Datatype identifier for the opaque datatype.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a pointer to an allocated string if successful;
        otherwise returns <code>NULL</code>.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tget_tag_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-ArrayCreate">H5Tarray_create</a>
<dt><strong>Signature:</strong>
    <dd><em>hid_t</em> <code>H5Tarray_create</code>(
                       <em>hid_t</em> <code>base</code>,
                       <em>int</em> <code>rank</code>,
                       <em>const hsize_t</em> <code>dims[/*rank*/]</code>,
                       <em>const int</em> <code>perm[/*rank*/]</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Creates an array datatype object.
<dt><strong>Description:</strong>
    <dd><code>H5Tarray_create</code> creates a new array datatype object.
         <p>
         <code>base</code> is the datatype of every element of the array, 
         i.e., of the number at each position in the array.
         <p>
         <code>rank</code> is the number of dimensions and the 
         size of each dimension is specified in the array <code>dims</code>.
         The value of <code>rank</code> is currently limited to
         <code>H5S_MAX_RANK</code> and must be greater than <code>0</code> 
         (zero).
         All dimension sizes specified in <code>dims</code> must be greater
         than <code>0</code> (zero).
         <p>
         The array <code>perm</code> is designed to contain the dimension 
         permutation, i.e. C versus FORTRAN array order.  
         &nbsp;
         <b><i>(The parameter </i><code>perm</code><i> is currently unused and is not yet implemented.)</i></b>
         <p>
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>base</code>
            <dd>IN: Datatype identifier for the array base datatype.
        <dt><em>int</em> <code>rank</code>
            <dd>IN: Rank of the array.
        <dt><em>const hsize_t</em> <code>dims[/*rank*/]</code>
            <dd>IN: Size of each array dimension.
        <dt><em>const int</em> <code>perm[/*rank*/]</code>
            <dd>IN: Dimension permutation.  
                &nbsp;
                <b><i>(Currently not implemented.)</i></b>
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5txxx_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetArrayNdims">H5Tget_array_ndims</a>
<dt><strong>Signature:</strong>
    <dd><em>int</em> <code>H5Tget_array_ndims</code>(
                       <em>hid_t</em> <code>adtype_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns the rank of an array datatype.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_array_ndims</code> returns the rank, 
        the number of dimensions, of an array datatype object.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>adtype_id</code>
            <dd>IN: Datatype identifier of array object.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns the rank of the array if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5txxx_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-GetArrayDims">H5Tget_array_dims</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t</em> <code>H5Tget_array_dims</code>(
                       <em>hid_t</em> <code>adtype_id</code>,
                       <em>hsize_t *</em><code>dims[]</code>,
                       <em>int *</em><code>perm[]</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Returns sizes of array dimensions and dimension permutations.
<dt><strong>Description:</strong>
    <dd><code>H5Tget_array_dims</code> returns the sizes of the dimensions
        and the dimension permutations of the specified array datatype object.
        <p>
        The sizes of the dimensions are returned in the array <code>dims</code>.
        The dimension permutations, i.e., C versus FORTRAN array order,
        are returned in the array <code>perm</code>.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>adtype_id</code>
            <dd>IN: Datatype identifier of array object.
        <dt><em>hsize_t *</em><code>dims[]</code>
            <dd>OUT: Sizes of array dimensions.
        <dt><em>int *</em><code>perm[]</code>
            <dd>OUT: Dimension permutations.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<!--
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5txxx_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
-->
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<dl>
<dt><strong>Name:</strong> <a name="Datatype-Close">H5Tclose</a>
<dt><strong>Signature:</strong>
    <dd><em>herr_t </em><code>H5Tclose</code>(<em>hid_t </em><code>type_id</code>
    )
<dt><strong>Purpose:</strong>
    <dd>Releases a datatype.  
<dt><strong>Description:</strong>
    <dd><code>H5Tclose</code> releases a datatype.  Further access 
        through the datatype identifier is illegal.  Failure to release 
        a datatype with this call will result in resource leaks.
<dt><strong>Parameters:</strong>
    <dl>
        <dt><em>hid_t</em> <code>type_id</code>
            <dd>Identifier of datatype to release.
    </dl>
<dt><strong>Returns:</strong>
    <dd>Returns a non-negative value if successful;
        otherwise returns a negative value.
<dt><strong>Non-C API(s):</strong>
    <dd><a href="fortran/h5t_FORTRAN.html#h5tclose_f" 
        target="FortranWin"><img src="Graphics/FORTRAN.gif" border=0></a>
        <!--
        <img src="Graphics/Java.gif"> 
        <img src="Graphics/C++.gif">
        -->
</dl>


<hr>
<center>
<table border=0 width=98%>
<tr><td valign=top align=left>
<a href="H5.intro.html">Introduction to HDF5</a>&nbsp;<br>
<a href="H5.user.html">HDF5 User Guide</a>&nbsp;<br>
<a href="index.html">Other HDF5 documents and links</a>&nbsp;<br>
<!--
<a href="Glossary.html">Glossary</a><br>
-->
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<td valign=top align=right>
And in this document, the 
<a href="RM_H5Front.html">HDF5 Reference Manual</a>&nbsp;&nbsp;
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<br>
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</td></tr>
</table>
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<address>
<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a> 

<br>
Last modified:  1 May 2002
<br>
Describes HDF5 Release 1.5, Unreleased Development Branch

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