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diff --git a/doc/html/DatatypesEnum.html b/doc/html/DatatypesEnum.html deleted file mode 100644 index 607030a..0000000 --- a/doc/html/DatatypesEnum.html +++ /dev/null @@ -1,926 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> -<html> - <head> - <title>Enumeration Data Types in the Data Type Interface (H5T)</title> - </head> - - <body bgcolor="#FFFFFF"> - - -<hr> -<center> -<table border=0 width=98%> -<tr><td valign=top align=left> - <a href="H5.intro.html">Introduction to HDF5</a> <br> - <a href="RM_H5Front.html">HDF5 Reference Manual</a> <br> - <a href="index.html">Other HDF5 documents and links</a> <br> - <!-- - <a href="Glossary.html">Glossary</a><br> - --> -</td> -<td valign=top align=right> - And in this document, the - <a href="H5.user.html">HDF5 User's Guide</a>: - <a href="Files.html">Files</a> - <br> - <a href="Datasets.html">Datasets</a> - <a href="Datatypes.html">Data Types</a> - <a href="Dataspaces.html">Dataspaces</a> - <a href="Groups.html">Groups</a> - <a href="References.html">References</a> - <br> - <a href="Attributes.html">Attributes</a> - <a href="Properties.html">Property Lists</a> - <a href="Errors.html">Error Handling</a> - <a href="Filters.html">Filters</a> - <a href="Caching.html">Caching</a> - <br> - <a href="Chunking.html">Chunking</a> - <a href="Debugging.html">Debugging</a> - <a href="Environment.html">Environment</a> - <a href="ddl.html">DDL</a> - <a href="Ragged.html">Ragged Arrays</a> -<!-- -<hr> -And in this document, the -<a href="H5.user.html">HDF5 User's Guide</a>: - <a href="Attributes.html">H5A</a> - <a href="Datasets.html">H5D</a> - <a href="Errors.html">H5E</a> - <a href="Files.html">H5F</a> - <a href="Groups.html">H5G</a> - <a href="Properties.html">H5P</a> - <a href="References.html">H5R & H5I</a> - <a href="Ragged.html">H5RA</a> - <a href="Dataspaces.html">H5S</a> - <a href="Datatypes.html">H5T</a> - <a href="Filters.html">H5Z</a> - <a href="Caching.html">Caching</a> - <a href="Chunking.html">Chunking</a> - <a href="Debugging.html">Debugging</a> - <a href="Environment.html">Environment</a> - <a href="ddl.html">DDL</a> ---> -</td></tr> -</table> -</center> -<hr> - - - <h1>The Data Type Interface (H5T) <font size=-1><i>(contitnued)</i></font></h1> - - <p align=right><font size=-1><i> - (Return to <a href="Datatypes.html#Datatypes_Enum">Data Types Interface (H5T)</a>.) - </font></i> - - <h2>7. Enumeration Data Types</h2> - - <h3>7.1. Introduction</h2> - - <p>An HDF enumeration data type is a 1:1 mapping between a set of - symbols and a set of integer values, and an order is imposed on - the symbols by their integer values. The symbols are passed - between the application and library as character strings and all - the values for a particular enumeration type are of the same - integer type, which is not necessarily a native type. - - <h3>7.2. Creation</h2> - - <p>Creation of an enumeration data type resembles creation of a - compound data type: first an empty enumeration type is created, - then members are added to the type, then the type is optionally - locked. - - <dl> - <dt><code>hid_t H5Tcreate(H5T_class_t <em>type_class</em>, - size_t <em>size</em>)</code> - <dd>This function creates a new empty enumeration data type based - on a native signed integer type. The first argument is the - constant <code>H5T_ENUM</code> and the second argument is the - size in bytes of the native integer on which the enumeration - type is based. If the architecture does not support a native - signed integer of the specified size then an error is - returned. - - <pre> -/* Based on a native signed short */ -hid_t hdf_en_colors = H5Tcreate(H5T_ENUM, sizeof(short));</pre> - - - <dt><code>hid_t H5Tenum_create(hid_t <em>base</em>)</code> - <dd>This function creates a new empty enumeration data type based - on some integer data type <em>base</em> and is a - generalization of the <code>H5Tcreate()</code> function. This - function is useful when creating an enumeration type based on - some non-native integer data type, but it can be used for - native types as well. - - <pre> -/* Based on a native unsigned short */ -hid_t hdf_en_colors_1 = H5Tenum_create(H5T_NATIVE_USHORT); - -/* Based on a MIPS 16-bit unsigned integer */ -hid_t hdf_en_colors_2 = H5Tenum_create(H5T_MIPS_UINT16); - -/* Based on a big-endian 16-bit unsigned integer */ -hid_t hdf_en_colors_3 = H5Tenum_create(H5T_STD_U16BE);</pre> - - - <dt><code>herr_t H5Tenum_insert(hid_t <em>etype</em>, const char - *<em>symbol</em>, void *<em>value</em>)</code> - <dd>Members are inserted into the enumeration data type - <em>etype</em> with this function. Each member has a symbolic - name <em>symbol</em> and some integer representation - <em>value</em>. The <em>value</em> argument must point to a value - of the same data type as specified when the enumeration type - was created. The order of member insertion is not important - but all symbol names and values must be unique within a - particular enumeration type. - - <pre> -short val; -H5Tenum_insert(hdf_en_colors, "RED", (val=0,&val)); -H5Tenum_insert(hdf_en_colors, "GREEN", (val=1,&val)); -H5Tenum_insert(hdf_en_colors, "BLUE", (val=2,&val)); -H5Tenum_insert(hdf_en_colors, "WHITE", (val=3,&val)); -H5Tenum_insert(hdf_en_colors, "BLACK", (val=4,&val));</pre> - - - <dt><code>herr_t H5Tlock(hid_t <em>etype</em>)</code> - <dd>This function locks a data type so it cannot be modified or - freed unless the entire HDF5 library is closed. Its use is - completely optional but using it on an application data type - makes that data type act like a predefined data type. - - <pre> -H5Tlock(hdf_en_colors);</pre> - - </dl> - - <h3>7.3. Integer Operations</h2> - - <p>Because an enumeration data type is derived from an integer - data type, any operation which can be performed on integer data - types can also be performed on enumeration data types. This - includes: - - <p> - <center> - <table> - <tr> - <td><code>H5Topen()</code></td> - <td><code>H5Tcreate()</code></td> - <td><code>H5Tcopy()</code></td> - <td><code>H5Tclose()</code></td> - </tr><tr> - <td><code>H5Tequal()</code></td> - <td><code>H5Tlock()</code></td> - <td><code>H5Tcommit()</code></td> - <td><code>H5Tcommitted()</code></td> - </tr><tr> - <td><code>H5Tget_class()</code></td> - <td><code>H5Tget_size()</code></td> - <td><code>H5Tget_order()</code></td> - <td><code>H5Tget_pad()</code></td> - </tr><tr> - <td><code>H5Tget_precision()</code></td> - <td><code>H5Tget_offset()</code></td> - <td><code>H5Tget_sign()</code></td> - <td><code>H5Tset_size()</code></td> - </tr><tr> - <td><code>H5Tset_order()</code></td> - <td><code>H5Tset_precision()</code></td> - <td><code>H5Tset_offset()</code></td> - <td><code>H5Tset_pad()</code></td> - </tr><tr> - <td><code>H5Tset_sign()</code></td> - </tr> - </table> - </center> - - <p>In addition, the new function <code>H5Tget_super()</code> will - be defined for all data types that are derived from existing - types (currently just enumeration types). - - <dl> - <dt><code>hid_t H5Tget_super(hid_t <em>type</em>)</code> - <dd>Return the data type from which <em>type</em> is - derived. When <em>type</em> is an enumeration data type then - the returned value will be an integer data type but not - necessarily a native type. One use of this function would be - to create a new enumeration type based on the same underlying - integer type and values but with possibly different symbols. - - <pre> -hid_t itype = H5Tget_super(hdf_en_colors); -hid_t hdf_fr_colors = H5Tenum_create(itype); -H5Tclose(itype); - -short val; -H5Tenum_insert(hdf_fr_colors, "ouge", (val=0,&val)); -H5Tenum_insert(hdf_fr_colors, "vert", (val=1,&val)); -H5Tenum_insert(hdf_fr_colors, "bleu", (val=2,&val)); -H5Tenum_insert(hdf_fr_colors, "blanc", (val=3,&val)); -H5Tenum_insert(hdf_fr_colors, "noir", (val=4,&val)); -H5Tlock(hdf_fr_colors);</pre> - </dl> - - <h3>7.4. Type Functions</h2> - - <p>A small set of functions is available for querying properties - of an enumeration type. These functions are likely to be used - by browsers to display data type information. - - <dl> - <dt><code>int H5Tget_nmembers(hid_t <em>etype</em>)</code> - <dd>When given an enumeration data type <em>etype</em> this - function returns the number of members defined for that - type. This function is already implemented for compound data - types. - - <br><br> - <dt><code>char *H5Tget_member_name(hid_t <em>etype</em>, unsigned - <em>membno</em>)</code> - <dd>Given an enumeration data type <em>etype</em> this function - returns the symbol name for the member indexed by - <em>membno</em>. Members are numbered from zero to - <em>N</em>-1 where <em>N</em> is the return value from - <code>H5Tget_nmembers()</code>. The members are stored in no - particular order. This function is already implemented for - compound data types. If an error occurs then the null pointer - is returned. The return value should be freed by calling - <code>free()</code>. - - <br><br> - <dt><code>herr_t H5Tget_member_value(hid_t <em>etype</em>, unsigned - <em>membno</em>, void *<em>value</em>/*out*/)</code> - <dd>Given an enumeration data type <em>etype</em> this function - returns the value associated with the member indexed by - <em>membno</em> (as described for - <code>H5Tget_member_name()</code>). The value returned - is in the domain of the underlying integer - data type which is often a native integer type. The - application should ensure that the memory pointed to by - <em>value</em> is large enough to contain the result (the size - can be obtained by calling <code>H5Tget_size()</code> on - either the enumeration type or the underlying integer type - when the type is not known by the C compiler. - - <pre> -int n = H5Tget_nmembers(hdf_en_colors); -unsigned u; -for (u=0; u<(unsigned)n; u++) { - char *symbol = H5Tget_member_name(hdf_en_colors, u); - short val; - H5Tget_member_value(hdf_en_colors, u, &val); - printf("#%u %20s = %d\n", u, symbol, val); - free(symbol); -}</pre> - - <p> - Output: - <pre> -#0 BLACK = 4 -#1 BLUE = 2 -#2 GREEN = 1 -#3 RED = 0 -#4 WHITE = 3</pre> - </dl> - - <h3>7.5. Data Functions</h2> - - <p>In addition to querying about the enumeration type properties, - an application may want to make queries about enumerated - data. These functions perform efficient mappings between symbol - names and values. - - <dl> - <dt><code>herr_t H5Tenum_valueof(hid_t <em>etype</em>, const char - *<em>symbol</em>, void *<em>value</em>/*out*/)</code> - <dd>Given an enumeration data type <em>etype</em> this function - returns through <em>value</em> the bit pattern associated with - the symbol name <em>symbol</em>. The <em>value</em> argument - should point to memory which is large enough to hold the result, - which is returned as the underlying integer data type specified - when the enumeration type was created, often a native integer - type. - - <br><br> - <dt><code>herr_t H5Tenum_nameof(hid_t <em>etype</em>, void - *<em>value</em>, char *<em>symbol</em>, size_t - <em>size</em>)</code> - <dd>This function translates a bit pattern pointed to by - <em>value</em> to a symbol name according to the mapping - defined in the enumeration data type <em>etype</em> and stores - at most <em>size</em> characters of that name (counting the - null terminator) to the <em>symbol</em> buffer. If the name is - longer than the result buffer then the result is not null - terminated and the function returns failure. If <em>value</em> - points to a bit pattern which is not in the domain of the - enumeration type then the first byte of the <em>symbol</em> - buffer is set to zero and the function fails. - - <pre> -short data[1000] = {4, 2, 0, 0, 5, 1, ...}; -int i; -char symbol[32]; - -for (i=0; i<1000; i++) { - if (H5Tenum_nameof(hdf_en_colors, data+i, symbol, - sizeof symbol))<0) { - if (symbol[0]) { - strcpy(symbol+sizeof(symbol)-4, "..."); - } else { - strcpy(symbol, "UNKNOWN"); - } - } - printf("%d %s\n", data[i], symbol); -} -printf("}\n");</pre> - - <p> - Output: - <pre> - -4 BLACK -2 BLUE -0 RED -0 RED -5 UNKNOWN -1 GREEN -...</pre> - </dl> - - <h3>7.6. Conversion</h2> - - <p>Enumerated data can be converted from one type to another - provided the destination enumeration type contains all the - symbols of the source enumeration type. The conversion operates - by matching up the symbol names of the source and destination - enumeration types to build a mapping from source value to - destination value. For instance, if we are translating from an - enumeration type that defines a sequence of integers as the - values for the colors to a type that defines a different bit for - each color then the mapping might look like this: - - <p><img src="EnumMap.gif" alt="Enumeration Mapping"> - - <p>That is, a source value of <code>2</code> which corresponds to - <code>BLUE</code> would be mapped to <code>0x0004</code>. The - following code snippet builds the second data type, then - converts a raw data array from one data type to another, and - then prints the result. - - <pre> -/* Create a new enumeration type */ -short val; -hid_t bits = H5Tcreate(H5T_ENUM, sizeof val); -H5Tenum_insert(bits, "RED", (val=0x0001,&val)); -H5Tenum_insert(bits, "GREEN", (val=0x0002,&val)); -H5Tenum_insert(bits, "BLUE", (val=0x0004,&val)); -H5Tenum_insert(bits, "WHITE", (val=0x0008,&val)); -H5Tenum_insert(bits, "BLACK", (val=0x0010,&val)); - -/* The data */ -short data[6] = {1, 4, 2, 0, 3, 5}; - -/* Convert the data from one type to another */ -H5Tconvert(hdf_en_colors, bits, 5, data, NULL); - -/* Print the data */ -for (i=0; i<6; i++) { - printf("0x%04x\n", (unsigned)(data[i])); -}</pre> - - <p> - Output: - <pre> - -0x0002 -0x0010 -0x0004 -0x0001 -0x0008 -0xffff</pre> - - <p>If the source data stream contains values which are not in the - domain of the conversion map then an overflow exception is - raised within the library, causing the application defined - overflow handler to be invoked (see - <code>H5Tset_overflow()</code>). If no overflow handler is - defined then all bits of the destination value will be set. - - <p>The HDF library will not provide conversions between enumerated - data and integers although the application is free to do so - (this is a policy we apply to all classes of HDF data - types). However, since enumeration types are derived from - integer types it is permissible to treat enumerated data as - integers and perform integer conversions in that context. - - <h3>7.7. Symbol Order</h2> - - <p>Symbol order is determined by the integer values associated - with each symbol. When the integer data type is a native type, - testing the relative order of two symbols is an easy process: - simply compare the values of the symbols. If only the symbol - names are available then the values must first be determined by - calling <code>H5Tenum_valueof()</code>. - - <pre> -short val1, val2; -H5Tenum_valueof(hdf_en_colors, "WHITE", &val1); -H5Tenum_valueof(hdf_en_colors, "BLACK", &val2); -if (val1 < val2) ...</pre> - - <p>When the underlying integer data type is not a native type then - the easiest way to compare symbols is to first create a similar - enumeration type that contains all the same symbols but has a - native integer type (HDF type conversion features can be used to - convert the non-native values to native values). Once we have a - native type we can compare symbol order as just described. If - <code>foreign</code> is some non-native enumeration type then a - native type can be created as follows: - - <pre> -int n = H5Tget_nmembers(foreign); -hid_t itype = H5Tget_super(foreign); -void *val = malloc(n * MAX(H5Tget_size(itype), sizeof(int))); -char *name = malloc(n * sizeof(char*)); -unsigned u; - -/* Get foreign type information */ -for (u=0; u<(unsigned)n; u++) { - name[u] = H5Tget_member_name(foreign, u); - H5Tget_member_value(foreign, u, - (char*)val+u*H5Tget_size(foreign)); -} - -/* Convert integer values to new type */ -H5Tconvert(itype, H5T_NATIVE_INT, n, val, NULL); - -/* Build a native type */ -hid_t native = H5Tenum_create(H5T_NATIVE_INT); -for (i=0; i<n; i++) { - H5Tenum_insert(native, name[i], ((int*)val)[i]); - free(name[i]); -} -free(name); -free(val);</pre> - - <p>It is also possible to convert enumerated data to a new type - that has a different order defined for the symbols. For - instance, we can define a new type, <code>reverse</code> that - defines the same five colors but in the reverse order. - - <pre> -short val; -int i; -char sym[8]; -short data[5] = {0, 1, 2, 3, 4}; - -hid_t reverse = H5Tenum_create(H5T_NATIVE_SHORT); -H5Tenum_insert(reverse, "BLACK", (val=0,&val)); -H5Tenum_insert(reverse, "WHITE", (val=1,&val)); -H5Tenum_insert(reverse, "BLUE", (val=2,&val)); -H5Tenum_insert(reverse, "GREEN", (val=3,&val)); -H5Tenum_insert(reverse, "RED", (val=4,&val)); - -/* Print data */ -for (i=0; i<5; i++) { - H5Tenum_nameof(hdf_en_colors, data+i, sym, sizeof sym); - printf ("%d %s\n", data[i], sym); -} - -puts("Converting..."); -H5Tconvert(hdf_en_colors, reverse, 5, data, NULL); - -/* Print data */ -for (i=0; i<5; i++) { - H5Tenum_nameof(reverse, data+i, sym, sizeof sym); - printf ("%d %s\n", data[i], sym); -}</pre> - - <p> - Output: - <pre> -0 RED -1 GREEN -2 BLUE -3 WHITE -4 BLACK -Converting... -4 RED -3 GREEN -2 BLUE -1 WHITE -0 BLACK</pre> - - <h3>7.8. Equality</h2> - - <p>The order that members are inserted into an enumeration type is - unimportant; the important part is the associations between the - symbol names and the values. Thus, two enumeration data types - will be considered equal if and only if both types have the same - symbol/value associations and both have equal underlying integer - data types. Type equality is tested with the - <code>H5Tequal()</code> function. - - <h3>7.9. Interacting with C's <code>enum</code> Type</h2> - - <p>Although HDF enumeration data types are similar to C - <code>enum</code> data types, there are some important - differences: - - <p> - <center> - <table border width="80%"> - <tr> - <th>Difference</th> - <th>Motivation/Implications</th> - </tr> - - <tr> - <td valign=top>Symbols are unquoted in C but quoted in - HDF.</td> - <td valign=top>This allows the application to manipulate - symbol names in ways that are not possible with C.</td> - </tr> - - <tr> - <td valign=top>The C compiler automatically replaces all - symbols with their integer values but HDF requires - explicit calls to do the same.</td> - <td valign=top>C resolves symbols at compile time while - HDF resolves symbols at run time.</td> - </tr> - - <tr> - <td valign=top>The mapping from symbols to integers is - <em>N</em>:1 in C but 1:1 in HDF.</td> - <td valign=top>HDF can translate from value to name - uniquely and large <code>switch</code> statements are - not necessary to print values in human-readable - format.</td> - </tr> - - <tr> - <td valign=top>A symbol must appear in only one C - <code>enum</code> type but may appear in multiple HDF - enumeration types.</td> - <td valign=top>The translation from symbol to value in HDF - requires the data type to be specified while in C the - data type is not necessary because it can be inferred - from the symbol.</td> - </tr> - - <tr> - <td valign=top>The underlying integer value is always a - native integer in C but can be a foreign integer type in - HDF.</td> - <td valign=top>This allows HDF to describe data that might - reside on a foreign architecture, such as data stored in - a file.</td> - </tr> - - <tr> - <td valign=top>The sign and size of the underlying integer - data type is chosen automatically by the C compiler but - must be fully specified with HDF.</td> - <td valign=top>Since HDF doesn't require finalization of a - data type, complete specification of the type must be - supplied before the type is used. Requiring that - information at the time of type creation was a design - decision to simplify the library.</td> - </tr> - </table> - </center> - - <p>The examples below use the following C data types: - - <p> - <table width="90%" bgcolor="white"> - <tr> - <td> - <code><pre> -/* English color names */ -typedef enum { - RED, - GREEN, - BLUE, - WHITE, - BLACK -} c_en_colors; - -/* Spanish color names, reverse order */ -typedef enum { - NEGRO - BLANCO, - AZUL, - VERDE, - ROJO, -} c_sp_colors; - -/* No enum definition for French names */ - </pre></code> - </td> - </tr> - </table> - - <h4>Creating HDF Types from C Types</h3> - - <p>An HDF enumeration data type can be created from a C - <code>enum</code> type simply by passing pointers to the C - <code>enum</code> values to <code>H5Tenum_insert()</code>. For - instance, to create HDF types for the <code>c_en_colors</code> - type shown above: - - <p> - <table width="90%" bgcolor="white"> - <tr> - <td> - <code><pre> - -c_en_colors val; -hid_t hdf_en_colors = H5Tcreate(H5T_ENUM, sizeof(c_en_colors)); -H5Tenum_insert(hdf_en_colors, "RED", (val=RED, &val)); -H5Tenum_insert(hdf_en_colors, "GREEN", (val=GREEN,&val)); -H5Tenum_insert(hdf_en_colors, "BLUE", (val=BLUE, &val)); -H5Tenum_insert(hdf_en_colors, "WHITE", (val=WHITE,&val)); -H5Tenum_insert(hdf_en_colors, "BLACK", (val=BLACK,&val));</pre></code> - </td> - </tr> - </table> - - <h4>Name Changes between Applications</h3> - - <p>Occassionally two applicatons wish to exchange data but they - use different names for the constants they exchange. For - instance, an English and a Spanish program may want to - communicate color names although they use different symbols in - the C <code>enum</code> definitions. The communication is still - possible although the applications must agree on common terms - for the colors. The following example shows the Spanish code to - read the values assuming that the applications have agreed that - the color information will be exchanged using Enlish color - names: - - <p> - <table width="90%" bgcolor="white"> - <tr> - <td> - <code><pre> - -c_sp_colors val, data[1000]; -hid_t hdf_sp_colors = H5Tcreate(H5T_ENUM, sizeof(c_sp_colors)); -H5Tenum_insert(hdf_sp_colors, "RED", (val=ROJO, &val)); -H5Tenum_insert(hdf_sp_colors, "GREEN", (val=VERDE, &val)); -H5Tenum_insert(hdf_sp_colors, "BLUE", (val=AZUL, &val)); -H5Tenum_insert(hdf_sp_colors, "WHITE", (val=BLANCO, &val)); -H5Tenum_insert(hdf_sp_colors, "BLACK", (val=NEGRO, &val)); - -H5Dread(dataset, hdf_sp_colors, H5S_ALL, H5S_ALL, H5P_DEFAULT, data);</pre></code> - </td> - </tr> - </table> - - - <h4>Symbol Ordering across Applications</h3> - - <p>Since symbol ordering is completely determined by the integer values - assigned to each symbol in the <code>enum</code> definition, - ordering of <code>enum</code> symbols cannot be preserved across - files like with HDF enumeration types. HDF can convert from one - application's integer values to the other's so a symbol in one - application's C <code>enum</code> gets mapped to the same symbol - in the other application's C <code>enum</code>, but the relative - order of the symbols is not preserved. - - <p>For example, an application may be defined to use the - definition of <code>c_en_colors</code> defined above where - <code>WHITE</code> is less than <code>BLACK</code>, but some - other application might define the colors in some other - order. If each application defines an HDF enumeration type based - on that application's C <code>enum</code> type then HDF will - modify the integer values as data is communicated from one - application to the other so that a <code>RED</code> value - in the first application is also a <code>RED</code> value in the - other application. - - <p>A case of this reordering of symbol names was also shown in the - previous code snippet (as well as a change of language), where - HDF changed the integer values so 0 (<code>RED</code>) in the - input file became 4 (<code>ROJO</code>) in the <code>data</code> - array. In the input file, <code>WHITE</code> was less than - <code>BLACK</code>; in the application the opposite is true. - - <p>In fact, the ability to change the order of symbols is often - convenient when the enumeration type is used only to group - related symbols that don't have any well defined order - relationship. - - <h4>Internationalization</h3> - - <p>The HDF enumeration type conversion features can also be used - to provide internationalization of debugging output. A program - written with the <code>c_en_colors</code> data type could define - a separate HDF data type for languages such as English, Spanish, - and French and cast the enumerated value to one of these HDF - types to print the result. - - <p> - <table width="90%" bgcolor="white"> - <tr> - <td> - <code><pre> - -c_en_colors val, *data=...; - -hid_t hdf_sp_colors = H5Tcreate(H5T_ENUM, sizeof val); -H5Tenum_insert(hdf_sp_colors, "ROJO", (val=RED, &val)); -H5Tenum_insert(hdf_sp_colors, "VERDE", (val=GREEN, &val)); -H5Tenum_insert(hdf_sp_colors, "AZUL", (val=BLUE, &val)); -H5Tenum_insert(hdf_sp_colors, "BLANCO", (val=WHITE, &val)); -H5Tenum_insert(hdf_sp_colors, "NEGRO", (val=BLACK, &val)); - -hid_t hdf_fr_colors = H5Tcreate(H5T_ENUM, sizeof val); -H5Tenum_insert(hdf_fr_colors, "OUGE", (val=RED, &val)); -H5Tenum_insert(hdf_fr_colors, "VERT", (val=GREEN, &val)); -H5Tenum_insert(hdf_fr_colors, "BLEU", (val=BLUE, &val)); -H5Tenum_insert(hdf_fr_colors, "BLANC", (val=WHITE, &val)); -H5Tenum_insert(hdf_fr_colors, "NOIR", (val=BLACK, &val)); - -void -nameof(lang_t language, c_en_colors val, char *name, size_t size) -{ - switch (language) { - case ENGLISH: - H5Tenum_nameof(hdf_en_colors, &val, name, size); - break; - case SPANISH: - H5Tenum_nameof(hdf_sp_colors, &val, name, size); - break; - case FRENCH: - H5Tenum_nameof(hdf_fr_colors, &val, name, size); - break; - } -}</pre></code> - </td> - </tr> - </table> - - <h3>7.10. Goals That Have Been Met</h2> - - <p>The main goal of enumeration types is to provide communication - of enumerated data using symbolic equivalence. That is, a - symbol written to a dataset by one application should be read as - the same symbol by some other application. - - <p> - <table width="90%"> - <tr> - <td valign=top><b>Architecture Independence</b></td> - <td valign=top>Two applications shall be able to exchange - enumerated data even when the underlying integer values - have different storage formats. HDF accomplishes this for - enumeration types by building them upon integer types.</td> - </tr> - - <tr> - <td valign=top><b>Preservation of Order Relationship</b></td> - <td valign=top>The relative order of symbols shall be - preserved between two applications that use equivalent - enumeration data types. Unlike numeric values that have - an implicit ordering, enumerated data has an explicit - order defined by the enumeration data type and HDF - records this order in the file.</td> - </tr> - - <tr> - <td valign=top><b>Order Independence</b></td> - <td valign=top>An application shall be able to change the - relative ordering of the symbols in an enumeration data - type. This is accomplished by defining a new type with - different integer values and converting data from one type - to the other.</td> - </tr> - - <tr> - <td valign=top><b>Subsets</b></td> - <td valign=top>An application shall be able to read - enumerated data from an archived dataset even after the - application has defined additional members for the - enumeration type. An application shall be able to write - to a dataset when the dataset contains a superset of the - members defined by the application. Similar rules apply - for in-core conversions between enumerated data - types.</td> - </tr> - - <tr> - <td valign=top><b>Targetable</b></td> - <td valign=top>An application shall be able to target a - particular architecture or application when storing - enumerated data. This is accomplished by allowing - non-native underlying integer types and converting the - native data to non-native data.</td> - </tr> - - <tr> - <td valign=top><b>Efficient Data Transfer</b></td> - <td valign=top>An application that defines a file dataset - that corresponds to some native C enumerated data array - shall be able to read and write to that dataset directly - using only Posix read and write functions. HDF already - optimizes this case for integers, so the same optimization - will apply to enumerated data. - </tr> - - <tr> - <td valign=top><b>Efficient Storage</b></td> - <td valign=top>Enumerated data shall be stored in a manner - which is space efficient. HDF stores the enumerated data - as integers and allows the application to chose the size - and format of those integers.</td> - </tr> - </table> - - - <p align=right><font size=-1><i> - (Return to <a href="Datatypes.html#Datatypes_Enum">Data Types Interface (H5T)</a>.) - </font></i> - -<hr> -<center> -<table border=0 width=98%> -<tr><td valign=top align=left> - <a href="H5.intro.html">Introduction to HDF5</a> <br> - <a href="RM_H5Front.html">HDF5 Reference Manual</a> <br> - <a href="index.html">Other HDF5 documents and links</a> <br> - <!-- - <a href="Glossary.html">Glossary</a><br> - --> -</td> -<td valign=top align=right> - And in this document, the - <a href="H5.user.html">HDF5 User's Guide</a>: - <a href="Files.html">Files</a> - <br> - <a href="Datasets.html">Datasets</a> - Data Types - <a href="Dataspaces.html">Dataspaces</a> - <a href="Groups.html">Groups</a> - <a href="References.html">References</a> - <br> - <a href="Attributes.html">Attributes</a> - <a href="Properties.html">Property Lists</a> - <a href="Errors.html">Error Handling</a> - <a href="Filters.html">Filters</a> - <a href="Caching.html">Caching</a> - <br> - <a href="Chunking.html">Chunking</a> - <a href="Debugging.html">Debugging</a> - <a href="Environment.html">Environment</a> - <a href="ddl.html">DDL</a> - <a href="Ragged.html">Ragged Arrays</a> -<!-- -<hr> -And in this document, the -<a href="H5.user.html">HDF5 User's Guide</a>: - <a href="Attributes.html">H5A</a> - <a href="Datasets.html">H5D</a> - <a href="Errors.html">H5E</a> - <a href="Files.html">H5F</a> - <a href="Groups.html">H5G</a> - <a href="Properties.html">H5P</a> - <a href="References.html">H5R & H5I</a> - <a href="Ragged.html">H5RA</a> - <a href="Dataspaces.html">H5S</a> - <a href="Datatypes.html">H5T</a> - <a href="Filters.html">H5Z</a> - <a href="Caching.html">Caching</a> - <a href="Chunking.html">Chunking</a> - <a href="Debugging.html">Debugging</a> - <a href="Environment.html">Environment</a> - <a href="ddl.html">DDL</a> ---> -</td></tr> -</table> -</center> - - -<hr> -<address> -<a href="mailto:hdfhelp@ncsa.uiuc.edu">HDF Help Desk</a> -</address> -<!-- Created: Thu Dec 4 14:57:32 EST 1997 --> -<!-- hhmts start --> -Last modified: 30 April 1999 -Footer modified: 3 July 2002 -<!-- hhmts end --> - -<br> -This file is longer used; the material has been integrated into Datatypes.html. - - -</body> -</html> |