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diff --git a/doc/html/Tutor/extend.html b/doc/html/Tutor/extend.html index 03b5972..55ff9e9 100644 --- a/doc/html/Tutor/extend.html +++ b/doc/html/Tutor/extend.html @@ -35,16 +35,19 @@ width=78 height=27 alt="NCSA"><P></A> <HR> <A NAME="def"> <H2>Creating an Extendible Dataset</H2> -An extendible dataset is one whose dimensions can grow. In HDF5, it is possible to define a dataset to have certain initial dimensions, then later -to increase the size of any of the initial dimensions. +An extendible dataset is one whose dimensions can grow. +HDF5 allows you to define a dataset to have certain initial dimensions, +then to later increase the size of any of the initial dimensions. <P> -HDF5 requires you to use chunking in order to define extendible datasets. Chunking makes it possible to extend datasets efficiently, without -having to reorganize storage excessively. +HDF5 requires you to use chunking to define extendible datasets. +This makes it possible to extend datasets efficiently without +having to excessively reorganize storage. <P> The following operations are required in order to write an extendible dataset: <OL> <LI>Declare the dataspace of the dataset to have unlimited dimensions for all dimensions that might eventually be extended. - <LI>Set dataset creation properties to enable chunking and create a dataset. + <LI>Set dataset creation properties to enable chunking. + <LI>Create the dataset. <LI>Extend the size of the dataset. </OL> <H2> Programming Example</H2> @@ -52,229 +55,197 @@ The following operations are required in order to write an extendible dataset: <H3><U>Description</U></H3> This example shows how to create a 3 x 3 extendible dataset, write to that dataset, extend the dataset to 10x3, and write to the dataset again. -[<A HREF="examples/h5_extend.c">Download h5_extend.c</A>] -<PRE> - -/************************************************************** - * - * This example shows how to work with extendible datasets. - * In the current version of the library a dataset MUST be - * chunked in order to be extendible. - * - * This example is derived from the h5_extend_write.c and - * h5_read_chunk.c examples that are in the "Introduction - * to HDF5". - * - *************************************************************/ - -#include "hdf5.h" - -#define FILE "ext.h5" -#define DATASETNAME "ExtendibleArray" -#define RANK 2 - -int -main (void) -{ - hid_t file; /* handles */ - hid_t dataspace, dataset; - hid_t filespace; - hid_t cparms; - hid_t memspace; - - hsize_t dims[2] = { 3, 3}; /* dataset dimensions - at creation time */ - hsize_t dims1[2] = { 3, 3}; /* data1 dimensions */ - hsize_t dims2[2] = { 7, 1}; /* data2 dimensions */ - - hsize_t maxdims[2] = {H5S_UNLIMITED, H5S_UNLIMITED}; - hsize_t size[2]; - hssize_t offset[2]; - hsize_t i,j; - herr_t status, status_n; - int data1[3][3] = { {1, 1, 1}, /* data to write */ - {1, 1, 1}, - {1, 1, 1} }; - - int data2[7] = { 2, 2, 2, 2, 2, 2, 2}; - - /* Variables used in reading data back */ - hsize_t chunk_dims[2] ={2, 5}; - hsize_t chunk_dimsr[2]; - hsize_t dimsr[2]; - int data_out[10][3]; - int rank, rank_chunk; - - /* Create the data space with unlimited dimensions. */ - dataspace = H5Screate_simple (RANK, dims, maxdims); - - /* Create a new file. If file exists its contents will be overwritten. */ - file = H5Fcreate (FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); - - /* Modify dataset creation properties, i.e. enable chunking */ - cparms = H5Pcreate (H5P_DATASET_CREATE); - status = H5Pset_chunk ( cparms, RANK, chunk_dims); - - /* Create a new dataset within the file using cparms - creation properties. */ - dataset = H5Dcreate (file, DATASETNAME, H5T_NATIVE_INT, dataspace, - cparms); - - /* Extend the dataset. This call assures that dataset is 3 x 3.*/ - size[0] = 3; - size[1] = 3; - status = H5Dextend (dataset, size); - - /* Select a hyperslab */ - filespace = H5Dget_space (dataset); - offset[0] = 0; - offset[1] = 0; - status = H5Sselect_hyperslab (filespace, H5S_SELECT_SET, offset, NULL, - dims1, NULL); - - /* Write the data to the hyperslab */ - status = H5Dwrite (dataset, H5T_NATIVE_INT, dataspace, filespace, - H5P_DEFAULT, data1); - - /* Extend the dataset. Dataset becomes 10 x 3 */ - dims[0] = dims1[0] + dims2[0]; - size[0] = dims[0]; - size[1] = dims[1]; - status = H5Dextend (dataset, size); - - /* Select a hyperslab */ - filespace = H5Dget_space (dataset); - offset[0] = 3; - offset[1] = 0; - status = H5Sselect_hyperslab (filespace, H5S_SELECT_SET, offset, NULL, - dims2, NULL); - - /* Define memory space */ - dataspace = H5Screate_simple (RANK, dims2, NULL); - - /* Write the data to the hyperslab */ - status = H5Dwrite (dataset, H5T_NATIVE_INT, dataspace, filespace, - H5P_DEFAULT, data2); - - /* Close resources */ - status = H5Dclose (dataset); - status = H5Sclose (dataspace); - status = H5Sclose (filespace); - status = H5Fclose (file); - -/**************************************************************** - Read the data back - ***************************************************************/ - - file = H5Fopen (FILE, H5F_ACC_RDONLY, H5P_DEFAULT); - dataset = H5Dopen (file, DATASETNAME); - filespace = H5Dget_space (dataset); - rank = H5Sget_simple_extent_ndims (filespace); - status_n = H5Sget_simple_extent_dims (filespace, dimsr, NULL); - - cparms = H5Dget_create_plist (dataset); - if (H5D_CHUNKED == H5Pget_layout (cparms)) - { - rank_chunk = H5Pget_chunk (cparms, 2, chunk_dimsr); - } - - memspace = H5Screate_simple (rank,dimsr,NULL); - status = H5Dread (dataset, H5T_NATIVE_INT, memspace, filespace, - H5P_DEFAULT, data_out); - printf("\n"); - printf("Dataset: \n"); - for (j = 0; j < dimsr[0]; j++) - { - for (i = 0; i < dimsr[1]; i++) - printf("%d ", data_out[j][i]); - printf("\n"); - } +<UL> +[<A HREF="examples/h5_extend.c">C example</A> ] + - <code>h5_extend.c</code><BR> +[<A HREF="examples/chunk.f90">FORTRAN example</A> ] + - <code>chunk.f90</code> +</UL> +<B>NOTE:</B> To download a tar file of the examples, including a Makefile, +please go to the <A HREF="references.html">References</A> page. - status = H5Pclose (cparms); - status = H5Dclose (dataset); - status = H5Sclose (filespace); - status = H5Sclose (memspace); - status = H5Fclose (file); -} -+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -</PRE> <A NAME="rem"> <H3><U>Remarks</U></H3> <P> <UL> -<LI>The function H5Pcreate creates a new property as an instance of - a property list. The signature of this function is as follows: -<PRE> - hid_t H5Pcreate ( H5P_class_t type ) -</PRE> +<LI>The routine <CODE>H5Pcreate</CODE> / <CODE>h5pcreate_f</CODE> +creates a new property as an instance of + a property list. The signature is as follows: +<P> +<I><B>C:</B></I> +<pre> + hid_t H5Pcreate (H5P_class_t classtype) +</pre> +<P> +<I><B>FORTRAN:</B></I> +<pre> + h5pcreate_f (classtype, prp_id, hdferr) + + classtype IN: INTEGER + prp_id OUT: INTEGER(HID_T) + hdferr OUT: INTEGER +</pre> +<P> <UL> -<LI>The parameter <I>type</I> is the type of property list to create.<BR> - The class types are: H5P_FILE_CREATE, H5P_FILE_ACCESS, H5P_DATASET_CREATE, - H5P_DATASET_XFER, and H5P_MOUNT +<LI>The parameter <I>classtype</I> is the type of property list to create. + Valid class types are as follows: +<center> +<table border=1> + <tr align=center> + <td><b>C</b></td> + <td><b>FORTRAN</b></td> + </tr><tr align=left> + <td><code> <BR> + H5P_FILE_CREATE <BR> + H5P_FILE_ACCESS <BR> + H5P_DATASET_CREATE<BR> + H5P_DATASET_XFER <BR> + H5P_MOUNT <BR><BR> + </code></td> + <td><code> <BR> + H5P_FILE_CREATE_F <BR> + H5P_FILE_ACCESS_F <BR> + H5P_DATASET_CREATE_F<BR> + H5P_DATASET_XFER_F <BR> + H5P_MOUNT_F <BR><BR> + </code></td> + </tr> +</table> +</center> +<LI>In C, the property list identifier is returned if successful; +otherwise a negative value is returned, if not. +In FORTRAN, the property list identifier is returned in <I>prp_id</I> +and the return value for the call is returned in <I>hdferr</I>. </UL> <P> -<LI>The function H5Pset_chunk sets the size of the chunks used +<LI>The routine <CODE>H5Pset_chunk</CODE> / <CODE>h5pset_chunk_f</CODE> +sets the size of the chunks used to store a chunked layout dataset. - The signature of this function is as follows: -<PRE> - herr_t H5Pset_chunk ( hid_t plist, int ndims, const hsize_t * dim ) -</PRE> + The signature of this routine is as follows: +<P> +<I><B>C:</B></I> +<pre> + herr_t H5Pset_chunk (hid_t prp_id, int ndims, + const hsize_t * dims) +</pre> +<P> +<I><B>FORTRAN:</B></I> +<pre> + h5pset_chunk_f (prp_id, ndims, dims, hdferr) + + prp_id IN: INTEGER(HID_T) + ndims IN: INTEGER + dims IN: INTEGER(HSIZE_T), DIMENSION(ndims) + hdferr OUT: INTEGER + +</pre> +<P> <UL> -<LI>The first parameter, <I>plist</I>, is the identifier for the property +<LI>The <em>prp_id</em> parameter is the identifier for the property list to query. -<LI>The second parameter, <I>ndims</I>, is the number of dimensions of +<LI>The <em>ndims</em> parameter is the number of dimensions of each chunk. -<LI>The third parameter, <I>dim</I>, is an array containing the size of +<LI>The <em>dims</em> parameter is an array containing the size of each chunk. +<LI>In C, a non-negative value is returned if successful; otherwise a + negative value is returned. + In FORTRAN, the return value is returned in <em>hdferr</em>: 0 if + successful and -1 otherwise. </UL> <P> -A non-negative value is returned if successful; otherwise a negative -value is returned. -<P> -<LI>The function H5Dextend extends a dataset that has an unlimited +<LI>The <CODE>H5Dextend</CODE> / <CODE>h5dextend_f</CODE> routine +extends a dataset that has an unlimited dimension. The signature is as follows: -<PRE> - herr_t H5Dextend ( hid_t dataset_id, const hsize_t * size ) -</PRE> +<P> +<I><B>C:</B></I> +<pre> + herr_t H5Dextend (hid_t dset_id, const hsize_t * size) +</pre> +<P> +<I><B>FORTRAN:</B></I> +<pre> + h5dextend_f (dset_id, size, hdferr) + + dset_id IN: INTEGER(HID_T) + size IN: INTEGER(HSIZE_T), DIMENSION(*) + hdferr OUT: INTEGER<BR> +</pre> +<P> <UL> -<LI>The first parameter, <I>dataset_id</I>, is the identifier of - the dataset. -<LI>The second parater, <I>size</I>, is an array containing the +<LI>The <em>dset_id</em> parameter is the dataset identifier. +<LI>The <em>size</em> parameter, is an array containing the new magnitude of each dimension. +<LI>In C, this function returns a non-negative value if successful and + a negative value otherwise. + In FORTRAN, the return value is returned in <em>hdferr</em>: + 0 if successful and -1 otherwise. </UL> <P> -This function returns a non-negative value if successful; otherwise -it returns a negative value. -<P> -<LI>The H5Dget_create_plist function returns an identifier for a +<LI>The <CODE>H5Dget_create_plist</CODE> / <CODE>h5dget_create_plist_f</CODE> +routine returns an identifier for a copy of the dataset creation property list for a dataset. <P> -<LI>The H5Pget_layout function returns the layout of the raw data for a -dataset. Valid types are H5D_COMPACT, H5D_CONTIGUOUS, and H5D_CHUNKED. +<LI>The C function, <CODE>H5Pget_layout</CODE>, returns the layout of the raw data for a +dataset. Valid types are <CODE>H5D_CONTIGUOUS</CODE> and +<CODE>H5D_CHUNKED</CODE>. +A FORTRAN routine for <CODE>H5Pget_layout</CODE> does not yet exist. +<P> +<LI>The <CODE>H5Pget_chunk</CODE> / <CODE>h5pget_chunk_f</CODE> +routine retrieves the size of chunks +for the raw data of a chunked layout dataset. +The signature is as follows: +<P> +<I><B>C:</B></I> +<pre> + int H5Pget_chunk (hid_t prp_id, int ndims, hsize_t * dims) +</pre> +<P> +<I><B>FORTRAN:</B></I> +<pre> + h5pget_chunk_f (prp_id, ndims, dims, hdferr) + + prp_id IN: INTEGER(HID_T) + ndims IN: INTEGER + dims OUT: INTEGER(HSIZE_T), DIMENSION(ndims) + hdferr OUT: INTEGER +</pre> <P> -<LI>The H5Pget_chunk function retrieves the size of chunks for the -raw data of a chunked layout dataset. -The signature of this function is: -<PRE> - int H5Pget_chunk ( hid_t plist, int max_ndims, hsize_t * dims ) -</PRE> <UL> -<LI>The first parameter, <I>plist</I>, is the identifier of the + +<LI>The <em>prp_id</em> parameter is the identifier of the property list to query. -<LI>The second parameter, <I>max_ndims</I>, is the size of the <I>dims</I> +<LI>The <em>ndims</em> parameter is the size of the <em>dims</em> array. -<LI>The third parameter, <I>dims</I>, is the array to store the chunk - dimensions +<LI>The <em>dims</em> parameter is the array in which to store the chunk + dimensions. +<LI>In C, this function returns the chunk dimensionality if successful + and a negative value otherwise. + In FORTRAN, the return value is returned in <em>hdferr</em>: + the chunked rank if successful and -1 otherwise. </UL> <P> -<LI>The H5Pclose function terminates access to a property list. - The signature of this function is: -<PRE> - herr_t H5Pclose ( hid_t plist ) -</PRE> -where <I>plist</I> is the identifier of the property list to terminate -access to. +<LI>The <CODE>H5Pclose</CODE> / <CODE>h5pclose_f</CODE> routine + terminates access to a property list. + The signature is as follows: +<P> +<I><B>C:</B></I> +<pre> + herr_t H5Pclose (hid_t prp_id) +</pre> +<P> +<I><B>FORTRAN:</B></I> +<pre> + h5pclose_f (prp_id, hdferr) + + prp_id IN: INTEGER(HID_T) + hdferr OUT: INTEGER +</pre> +<P> +<ul> +<li>The <em>prp_id</em> parameter is the identifier of the property list + to terminate access to. +</ul> </UL> @@ -301,8 +272,9 @@ access to. <!-- <A HREF="helpdesk.mail.html"> --> <A HREF="mailto:hdfhelp@ncsa.uiuc.edu"> hdfhelp@ncsa.uiuc.edu</A> -<BR> <H6>Last Modified: August 27, 1999</H6><BR> +<BR> <H6>Last Modified: January 19, 2000</H6><BR> <!-- modified by Barbara Jones - bljones@ncsa.uiuc.edu --> +<!-- modified by Frank Baker - fbaker@ncsa.uiuc.edu --> </FONT> <BR> <!-- <A HREF="mailto:hdfhelp@ncsa.uiuc.edu"> --> |