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| author | Quincey Koziol <koziol@hdfgroup.org> | 1998-07-08 14:54:54 (GMT) |
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| committer | Quincey Koziol <koziol@hdfgroup.org> | 1998-07-08 14:54:54 (GMT) |
| commit | bd1e676c521d881b3143829f493a28b5ced1294b (patch) | |
| tree | 69c50f9fe21ce87f293d8617a6bd51b4cc1e0244 /doc/html/Dataspaces.html | |
| parent | 73345095897d9698bb1f2f7df830bf80a56dc65a (diff) | |
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diff --git a/doc/html/Dataspaces.html b/doc/html/Dataspaces.html new file mode 100644 index 0000000..d2579b6 --- /dev/null +++ b/doc/html/Dataspaces.html @@ -0,0 +1,568 @@ +<HTML> +<HEAD> + <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> + <TITLE>The Data Space Interface (H5S)</TITLE> +</HEAD> +<BODY> + +<H1> +The Dataspace Interface (H5S)</H1> + +<H2> +1. Introduction</H2> +The dataspace interface (H5S) provides a mechanism to describe the positions +of the elements of a dataset and is designed in such a way as to allow +new features to be easily added without disrupting applications that use +the dataspace interface. A dataset (defined with the dataset interface) is +composed of a collection of raw data points of homogeneous type, defined in the +datatype (H5T) interface, organized according to the dataspace with this +interface. + +<P>A dataspace describes the locations that dataset elements are located at. +A dataspace is either a regular N-dimensional array of data points, +called a <I>simple</I> dataspace, or a more general collection of data +points organized in another manner, called a <I>complex</I> dataspace. +A <I>scalar</I> dataspace is a special case of the <I>simple</I> data +space and is defined to be a 0-dimensional single data point in size. Currently +only <I>scalar</I> and <I>simple</I> dataspaces are supported with this version +of the H5S interface. +<I>Complex</I> dataspaces will be defined and implemented in a future +version. <I>Complex</I> dataspaces are intended to be used for such structures +which are awkward to express in <I>simple</I> dataspaces, such as irregularly +gridded data or adaptive mesh refinement data. This interface provides +functions to set and query properties of a dataspace. + +<P>Operations on a dataspace include defining or extending the extent of +the dataspace, selecting portions of the dataspace for I/O and storing the +dataspaces in the file. The extent of a dataspace is the range of coordinates +over which dataset elements are defined and stored. Dataspace selections are +subsets of the extent (up to the entire extent) which are selected for some +operation. + +<P>For example, a 2-dimensional dataspace with an extent of 10 by 10 may have +the following very simple selection: + <br><br><center> + <table border cellpadding=4> + <tr align=center> + <th > </th> <th >0</th> <th >1</th> <th >2</th> <th >3</th> <th >4</th> <th >5</th> <th >6</th> <th >7</th> <th >8</th> <th >9</th> + <tr align=center> + <th>0</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>1</th> + <td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>2</th> + <td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>3</th> + <td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>4</th> + <td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>5</th> + <td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>6</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>7</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>8</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>9</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + </table> + <br><strong>Example 1: Contiguous rectangular selection</strong> + </center> + + +<br>Or, a more complex selection may be defined: + <br><br><center> + <table border cellpadding=4> + <tr align=center> + <th > </th> <th >0</th> <th >1</th> <th >2</th> <th >3</th> <th >4</th> <th >5</th> <th >6</th> <th >7</th> <th >8</th> <th >9</th> + <tr align=center> + <th>0</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>1</th> + <td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>2</th> + <td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>3</th> + <td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>4</th> + <td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>5</th> + <td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>6</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>7</th> + <td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>8</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>9</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + </table> + <br><strong>Example 2: Non-contiguous selection</strong> + </center> + +<P>Selections within dataspaces have an offset within the extent which is used +to locate the selection within the extent of the dataspace. Selection offsets +default to 0 in each dimension, but may be changed to move the selection within +a dataspace. In example 2 above, if the offset was changed to 1,1, the selection +would look like this: + <br><br><center> + <table border cellpadding=4> + <tr align=center> + <th > </th> <th >0</th> <th >1</th> <th >2</th> <th >3</th> <th >4</th> <th >5</th> <th >6</th> <th >7</th> <th >8</th> <th >9</th> + <tr align=center> + <th>0</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>1</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>2</th> + <td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td> + <tr align=center> + <th>3</th> + <td>-</td><td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>4</th> + <td>-</td><td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td> + <tr align=center> + <th>5</th> + <td>-</td><td>-</td><td>X</td><td>-</td><td>X</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>6</th> + <td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>X</td><td>-</td><td>-</td> + <tr align=center> + <th>7</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>8</th> + <td>-</td><td>-</td><td>-</td><td>X</td><td>X</td><td>X</td><td>X</td><td>-</td><td>-</td><td>-</td> + <tr align=center> + <th>9</th> + <td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td> + </table> + <br><strong>Example 3: Non-contiguous selection with 1,1 offset</strong> + </center> + +<P>Selections also have an linearization ordering of the points selected +(defaulting to "C" order, ie. last dimension changing fastest). The +linearization order may be specified for each point or it may be chosen by +the axis of the dataspace. For example, with the default "C" ordering, +example 1's selected points are iterated through in this order: (1,1), (2,1), +(3,1), (1,2), (2,2), etc. With "FORTRAN" ordering, example 1's selected points +would be iterated through in this order: (1,1), (1,2), (1,3), (1,4), (1,5), +(2,1), (2,2), etc. + +<P>A dataspace may be stored in the file as a permanent object, to allow many +datasets to use a commonly defined dataspace. Dataspaces with extendable +extents (ie. unlimited dimensions) are not able to be stored as permanent +dataspaces. + +<P>Dataspaces may be created using an existing permanent dataspace as a +container to locate the new dataspace within. These dataspaces are complete +dataspaces and may be used to define datasets. A dataspaces with a "parent" +can be queried to determine the parent dataspace and the location within the +parent. These dataspaces must currently be the same number of dimensions as +the parent dataspace. + +<H2> 2. General Dataspace Operations</H2> +The functions defined in this section operate on dataspaces as a whole. +New dataspaces can be created from scratch or copied from existing data +spaces. When a dataspace is no longer needed its resources should be released +by calling <TT>H5Sclose()</TT>. +<DL> + +<DT> +<TT>hid_t H5Screate(H5S_class_t <I>type</I>)</TT></DT> + +<DD> + This function creates a new dataspace of a particular <I>type</I>. The +types currently supported are H5S_SCALAR, H5S_SIMPLE, or H5S_NONE, although +others are planned to be added later. The H5S_NONE dataspace can only hold a +selection, not an extent. +</DD> + +<DT> +<TT>hid_t H5Sopen(hid_t <I>location</I>, const char *<I>name</I>)</TT></DT> + +<DD> + This function opens a permanent dataspace for use in an application. +The <I>location</I> argument is a file or group ID and <I>name</I> is +an absolute or relative path to the permanent dataspace. The dataspace ID which +is returned is a handle to a permanent dataspace which can't be modified. +</DD> + +<DT> +<TT>hid_t H5Scopy (hid_t <I>space</I>)</TT></DT> + +<DD> + This function creates a new dataspace which is an exact copy of the +dataspace <I>space</I>. +</DD> + +<DT> +<TT>hid_t H5Ssubspace (hid_t <I>space</I>)</TT></DT> + +<DD> + This function uses the currently defined selection and offset in <I>space</I> +to create a dataspace which is located within <I>space</I>. The <I>space</I> +dataspace must be a sharable dataspace located in the file, not a dataspace for +a dataset. The relationship of the new dataspace within the existing dataspace +is preserved when the new dataspace is used to create datasets. Currently, +only subspaces which are equivalent to simple dataspaces (ie. rectangular +contiguous areas) are allowed. A subspace is not "simplified" or reduced in +the number of dimensions used if the selection is "flat" in one dimension, they +always have the same number of dimensions as their parent dataspace. +</DD> + +<DT> +<TT>herr_t H5Scommit (hid_t <I>location</I>, const char *<I>name</I>, hid_t <I>space</I>)</TT></DT> + +<DD> + The dataspaces specified with <I>space</I> is stored in the file specified +by <I>location</I>. <I>Location</I> may be either a file or group handle +and <I>name</I> is an absolute or relative path to the location to store the +dataspace. After this call, the dataspace is permanent and can't be modified. +</DD> + +<DT> +<TT>herr_t H5Sclose (hid_t <I>space</I>)</TT></DT> + +<DD> +Releases resources associated with a dataspace. Subsequent use of the +dataspace identifier after this call is undefined. +</DD> + +<DT> +<TT>H5S_class_t H5Sget_class (hid_t <I>space</I>)</TT></DT> + +<DD> +Query a dataspace to determine the current class of a dataspace. The value +which is returned is one of: H5S_SCALAR, H5S_SIMPLE, or H5S_NONE on success or +FAIL on failure. +</DD> +</DL> + + +<H2> 3. Dataspace Extent Operations</H2> +These functions operate on the extent portion of a dataspace. + +<DL> +<DT> +<TT>herr_t H5Sset_extent_simple (hid_t <I>space</I>, int <I>rank</I>, const hsize_t +*<I>current_size</I>, const hsize_t *<I>maximum_size</I>)</TT></DT> + +<DD> +Sets or resets the size of an existing dataspace, where <I>rank</I> is +the dimensionality, or number of dimensions, of the dataspace. +<I>current_size</I> is an array of size <I>rank</I> which contains the new size +of each dimension in the dataspace. <I>maximum_size</I> is an array of size +<I>rank</I> which contains the maximum size of each dimension in the dataspace. +Any previous extent is removed from the dataspace, the dataspace type is set to +H5S_SIMPLE and the extent is set as specified. +</DD> + +<DT> +<TT>herr_t H5Sset_extent_none (hid_t <I>space</I>)</TT></DT> + +<DD> +Removes the extent from a dataspace and sets the type to H5S_NONE. +</DD> + +<DT> +<TT>herr_t H5Sextent_copy (hid_t <I>dest_space</I>, + hid_t <I>source_space</I>)</TT></DT> + +<DD> +Copies the extent from <I>source_space</I> to <I>dest_space</I>, which may +change the type of the dataspace. Returns non-negative on success, negative on +failure. +</DD> + +<DT> +<TT>hsize_t H5Sextent_npoints (hid_t <I>space</I>)</TT></DT> + +<DD> +This function determines the number of elements in a dataspace. For example, a +simple 3-dimensional dataspace with dimensions 2, 3 and 4 would have 24 +elements. +Returns the number of elements in the dataspace, negative on failure. +</DD> + +<DT> +<TT>int H5Sextent_ndims (hid_t <I>space</I>)</TT></DT> + +<DD> +This function determines the dimensionality (or rank) of a dataspace. +Returns the number of dimensions in the dataspace, negative on failure. +</DD> + +<DT> +<TT>herr_t H5Sextent_dims (hid_t <I>space</I>, hsize_t *<I>dims</I>, + hsize_t *<I>max</I>)</TT></DT> + +<DD> +The function retrieves the size of the extent of the dataspace <I>space</I> by +placing the size of each dimension in the array <I>dims</I>. Also retrieves +the size of the maximum extent of the dataspace, placing the results in +<I>max</I>. +Returns non-negative on success, negative on failure. +</DD> + +</DL> + +<H2> 4. Dataspace Selection Operations</H2> +Selections are maintained separately from extents in dataspaces and operations +on the selection of a dataspace do not affect the extent of the dataspace. +Selections are independent of extent type and the boundaries of selections are +reconciled with the extent at the time of the data transfer. Selection offsets +apply a selection to a location within an extent, allowing the same selection +to be moved within the extent without requiring a new selection to be specified. +Offsets default to 0 when the dataspace is created. Offsets are applied when +an I/O transfer is performed (and checked during calls to H5Sselect_valid). +Selections have an iteration order for the points selected, which can be any +permutation of the dimensions involved (defaulting to 'C' array order) or a +specific order for the selected points, for selections composed of single array +elements with H5Sselect_elements. Selections can also be copied or combined +together in various ways with H5Sselect_op. Further methods of selecting +portions of a dataspace may be added in the future. + +<DL> +<DT> +<TT>herr_t H5Sselect_hyperslab (hid_t <I>space</I>, h5s_selopt_t <I>op</I>, + const hssize_t * <I>start</I>, const hsize_t * <I>stride</I>, + const hsize_t * <I>count</I>, const hsize_t * <I>block</I>)</TT></DT> + +<DD> +This function selects a hyperslab region to add to the current selected region +for the <I>space</I> dataspace. The <I>start</I>, <I>stride</I>, <I>count</I> +and <I>block</I> arrays must be the same size as the rank of the dataspace. +The selection operator <I>op</I> determines how the new selection is to be +combined with the already existing selection for the dataspace. Currently, +only the H5S_SELECT_SET operator is supported, which replaces the existing +selection with the parameters from this call. Overlapping blocks are not +supported with the H5S_SELECT_SET operator. +<P>The <I>start</I> array determines the starting coordinates of the hyperslab +to select. The <I>stride</I> array chooses array locations from the dataspace +with each value in the <I>stride</I> array determining how many elements to move +in each dimension. Setting a value in the <I>stride</I> array to 1 moves to +each element in that dimension of the dataspace, setting a value of 2 in a +location in the <I>stride</I> array moves to every other element in that +dimension of the dataspace. In other words, the <I>stride</I> determines the +number of elements to move from the <I>start</I> location in each dimension. +Stride values of 0 are not allowed. If the <I>stride</I> parameter is <TT>NULL</TT>, +a contiguous hyperslab is selected (as if each value in the <I>stride</I> array +was set to all 1's). The <I>count</I> array determines how many blocks to +select from the dataspace, in each dimension. The <I>block</I> array determines +the size of the element block selected from the dataspace. If the <I>block</I> +parameter is set to <TT>NULL</TT>, the block size defaults to a single element +in each dimension (as if the <I>block</I> array was set to all 1's). +<P>For example, in a 2-dimensional dataspace, setting <I>start</I> to [1,1], +<I>stride</I> to [4,4], <I>count</I> to [3,7] and <I>block</I> to [2,2] selects +21 2x2 blocks of array elements starting with location (1,1) and selecting +blocks at locations (1,1), (5,1), (9,1), (1,5), (5,5), etc. +<P>Regions selected with this function call default to 'C' order iteration when +I/O is performed. +</DD> + +<DT> +<TT>herr_t H5Sselect_elements (hid_t <I>space</I>, h5s_selopt_t <I>op</I>, + const size_t <I>num_elements</I>, const hssize_t *<I>coord</I>[])</TT></DT> + +<DD> +This function selects array elements to be included in the selection for the +<I>space</I> dataspace. The number of elements selected must be set with the +<I>num_elements</I>. The <I>coord</I> array is a two-dimensional array of size +<dataspace rank> by <<I>num_elements</I>> in size (ie. a list of +coordinates in the array). The order of the element coordinates in the +<I>coord</I> array also specifies the order that the array elements are +iterated through when I/O is performed. Duplicate coordinate locations are not +checked for. + +<P>The selection operator <I>op</I> determines how the new selection is to be +combined with the already existing selection for the dataspace. Currently, +only the H5S_SELECT_SET operator is supported, which replaces the existing +selection with the parameters from this call. When operators other than +H5S_SELECT_SET are used to combine a new selection with an existing selection, +the selection ordering is reset to 'C' array ordering. +</DD> + +<DT> +<TT>herr_t H5Sselect_all (hid_t <I>space</I>)</TT></DT> + +<DD> +This function selects the special H5S_SELECT_ALL region for the <I>space</I> +dataspace. H5S_SELECT_ALL selects the entire dataspace for any dataspace is is +applied to. +</DD> + +<DT> +<TT>herr_t H5Sselect_none (hid_t <I>space</I>)</TT></DT> + +<DD> +This function resets the selection region for the <I>space</I> +dataspace not to include any elements. +</DD> + +<DT> +<TT>herr_t H5Sselect_op (hid_t <I>space1</I>, h5s_selopt_t <I>op</I>, + hid_t <I>space2</I>)</TT></DT> + +<DD> +Uses <I>space2</I> to perform an operation on <I>space1</I>. The valid +operations for <I>op</I> are: +<DL> + <DT>H5S_SELECT_COPY + <DD>Copies the selection from <I>space2</I> into <I>space1</I>, removing any + previously defined selection for <I>space1</I>. The selection order + and offset are also copied to <I>space1</I> + <DT>H5S_SELECT_UNION + <DD>Performs a set union of the selection of the dataspace <I>space2</I> + with the selection from the dataspace <I>space1</I>, with the result + being stored in <I>space1</I>. The selection order for <I>space1</I> is + reset to 'C' order. + <DT>H5S_SELECT_INTERSECT + <DD>Performs an set intersection of the selection from <I>space2</I> with + <I>space1</I>, with the result being stored in <I>space1</I>. The + selection order for <I>space1</I> is reset to 'C' order. + <DT>H5S_SELECT_DIFFERENCE + <DD>Performs a set difference of the selection from <I>space2</I> with + <I>space1</I>, with the result being stored in <I>space1</I>. The + selection order for <I>space1</I> is reset to 'C' order. +</DL> + +</DD> + +<DT> +<TT>herr_t H5Sselect_order (hid_t <I>space</I>, + hsize_t <I>perm_vector</I>[])</TT></DT> + +<DD> +This function selects the order to iterate through the dimensions of a dataspace +when performing I/O on a selection. If a specific order has already been +selected for the selection with H5Sselect_elements, this function will remove +it and use a dimension oriented ordering on the selected elements. The elements +of the <I>perm_vector</I> array must be unique and between 0 and the rank of the +dataspace, minus 1. The order of the elements in <I>perm_vector</I> specify +the order to iterate through the selection for each dimension of the dataspace. +To iterate through a 3-dimensional dataspace selection in 'C' order, specify +the elements of the <I>perm_vector</I> as [0, 1, 2], for FORTRAN order they +would be [2, 1, 0]. Other orderings, such as [1, 2, 0] are also possible, but +may execute slower. +</DD> + +<DT> +<TT>hbool_t H5Sselect_valid (hid_t <I>space</I>)</TT></DT> + +<DD> +This function verifies that the selection for a dataspace is within the extent +of the dataspace, if the currently set offset for the dataspace is used. +Returns TRUE if the selection is contained within the extent, FALSE if it +is not contained within the extent and FAIL on error conditions (such as if +the selection or extent is not defined). +</DD> + +<DT> +<TT>hsize_t H5Sselect_npoints (hid_t <I>space</I>)</TT></DT> + +<DD> +This function determines the number of elements in the current selection +of a dataspace. +</DD> + +<DT> +<TT>herr_t H5Soffset_simple (hid_t <I>space</I>, const hssize_t * + <I>offset</I>)</TT></DT> + +<DD> +Sets the offset of a simple dataspace <I>space</I>. The <I>offset</I> array +must be the same number of elements as the number of dimensions for the +dataspace. If the <I>offset</I> array is set to <TT>NULL</TT>, the offset +for the dataspace is reset to 0. +</DD> + +</DL> + +<H2> 5. Misc. Dataspace Operations</H2> + +<DL> + +<DT> +<TT>herr_t H5Slock (hid_t <I>space</I>)</TT></DT> + +<DD> +Locks the dataspace so that it cannot be modified or closed. When the library +exits, the dataspace will be unlocked and closed. +</DD> + +<DT> +<TT>hid_t H5Screate_simple(int <I>rank</I>, const hsize_t *<I>current_size</I>, + const hsize_t *<I>maximum_size</I>)</TT></DT> + +<DD> + This function is a "convenience" wrapper to create a simple dataspace +and set it's extent in one call. It is equivalent to calling H5Screate +and H5Sset_extent_simple() in two steps. +</DD> + +<DT> +<TT>int H5Sis_subspace(hid_t <I>space</I>)</TT></DT> + +<DD> + This function returns positive if <I>space</I> is located within another +dataspace, zero if it is not, and negative on a failure. +</DD> + +<DT> +<TT>char *H5Ssubspace_name(hid_t <I>space</I>)</TT></DT> + +<DD> + This function returns the name of the named dataspace that <I>space</I> +is located within. If <I>space</I> is not located within another dataspace, +or an error occurs, NULL is returned. The application is responsible for +freeing the string returned. +</DD> + +<DT> +<TT>herr_t H5Ssubspace_location(hid_t <I>space</I>, hsize_t *<I>loc</I>)</TT></DT> + +<DD> + If <I>space</I> is located within another dataspace, this function puts +the location of the origin of <I>space</I> in the <I>loc</I> array. The <I>loc</I> +array must be at least as large as the number of dimensions of <I>space</I>. +If <I>space</I> is not located within another dataspace +or an error occurs, a negative value is returned, otherwise a non-negative value +is returned. +</DD> + +</DL> + +<HR> +<ADDRESS> +<A HREF="mailto:matzke@llnl.gov">Robb Matzke</A></ADDRESS> + +<ADDRESS> +<A HREF="mailto:koziol@ncsa.uiuc.edu">Quincey Koziol</A></ADDRESS> + +<BR><!-- Created: Thu Dec 4 14:57:32 EST 1997 --><!-- hhmts start -->Last +modified: Thu May 28 15:12:04 EST 1998 <!-- hhmts end --> +</BODY> +</HTML> |