summaryrefslogtreecommitdiffstats
path: root/doc/html/Tutor/selectc.html
diff options
context:
space:
mode:
authorFrank Baker <fbaker@hdfgroup.org>2000-12-22 20:47:59 (GMT)
committerFrank Baker <fbaker@hdfgroup.org>2000-12-22 20:47:59 (GMT)
commitc1d537db2b803d6908fe3f21f62c592c9cd2bf70 (patch)
tree56a6cb7f00a6fbec3b071722df9705e744368073 /doc/html/Tutor/selectc.html
parentd4c3773742b8dee426e7325fee4e8fc4015f2802 (diff)
downloadhdf5-c1d537db2b803d6908fe3f21f62c592c9cd2bf70.zip
hdf5-c1d537db2b803d6908fe3f21f62c592c9cd2bf70.tar.gz
hdf5-c1d537db2b803d6908fe3f21f62c592c9cd2bf70.tar.bz2
[svn-r3196]
Purpose: Adding Tutorial to development branch (R 1.4) Platforms tested: IE 5
Diffstat (limited to 'doc/html/Tutor/selectc.html')
-rw-r--r--doc/html/Tutor/selectc.html296
1 files changed, 296 insertions, 0 deletions
diff --git a/doc/html/Tutor/selectc.html b/doc/html/Tutor/selectc.html
new file mode 100644
index 0000000..e01d9db
--- /dev/null
+++ b/doc/html/Tutor/selectc.html
@@ -0,0 +1,296 @@
+<HTML><HEAD>
+<TITLE>HDF5 Tutorial - Selections using H5Sselect_elements and H5Scopy
+</TITLE>
+</HEAD>
+
+<body bgcolor="#ffffff">
+
+<!-- BEGIN MAIN BODY -->
+
+<A HREF="http://www.ncsa.uiuc.edu/"><img border=0
+src="http://www.ncsa.uiuc.edu/Images/NCSAhome/footerlogo.gif"
+width=78 height=27 alt="NCSA"><P></A>
+
+ [ <A HREF="title.html"><I>HDF5 Tutorial Top</I></A> ]
+<H1>
+<BIG><BIG><BIG><FONT COLOR="#c101cd">Selections using H5Sselect_elements and H5SCopy</FONT>
+</BIG></BIG></BIG></H1>
+
+<hr noshade size=1>
+
+<BODY>
+<H2>Contents:</H2>
+<UL>
+ <LI> <A HREF="#def">Selecting Independent Points and Copying a Dataspace</A>
+ <LI> Programming Example
+ <UL>
+ <LI> <A HREF="#desc">Description</A>
+ <LI> <A HREF="#rem">Remarks</A>
+ <LI> <A HREF="#fc">File Contents</A>
+ </UL>
+</UL>
+<HR>
+<A NAME="def">
+<H2>Selecting Independent Points and Copying a Dataspace</h2>
+You can select independent points to read or write to in a
+dataspace by use of the H5Sselect_elements function.
+<P>
+The H5Scopy function allows you to make an exact copy of a dataspace,
+which can help cut down on the number of function calls needed when
+selecting a dataspace.
+<P>
+<H2> Programming Example</H2>
+<A NAME="desc">
+<H3><U>Description</U></H3>
+This example shows you how to use H5Sselect_elements to select individual
+points in a dataset and how to use H5Scopy to make a copy of a dataspace.
+
+[ <A HREF="examples/h5_copy.c">Download h5_copy.c</A> ]
+<PRE>
+/***********************************************************************/
+/* */
+/* PROGRAM: h5_copy.c */
+/* PURPOSE: Shows how to use the H5SCOPY function. */
+/* DESCRIPTION: */
+/* This program creates two files, copy1.h5, and copy2.h5. */
+/* In copy1.h5, it creates a 3x4 dataset called 'Copy1', */
+/* and write 0's to this dataset. */
+/* In copy2.h5, it create a 3x4 dataset called 'Copy2', */
+/* and write 1's to this dataset. */
+/* It closes both files, reopens both files, selects two */
+/* points in copy1.h5 and writes values to them. Then it */
+/* does an H5Scopy from the first file to the second, and */
+/* writes the values to copy2.h5. It then closes the */
+/* files, reopens them, and prints the contents of the */
+/* two datasets. */
+/* */
+/***********************************************************************/
+
+#include "hdf5.h"
+#define FILE1 "copy1.h5"
+#define FILE2 "copy2.h5"
+
+#define RANK 2
+#define DIM1 3
+#define DIM2 4
+#define NUMP 2
+
+int main (void)
+{
+ hid_t file1, file2, dataset1, dataset2;
+ hid_t mid1, mid2, fid1, fid2;
+ hsize_t fdim[] = {DIM1, DIM2};
+ hsize_t mdim[] = {DIM1, DIM2};
+ hsize_t start[2], stride[2], count[2], block[2];
+ int buf1[DIM1][DIM2];
+ int buf2[DIM1][DIM2];
+ int bufnew[DIM1][DIM2];
+ int val[] = {53, 59};
+ hsize_t marray[] = {2};
+ hssize_t coord[NUMP][RANK];
+ herr_t ret;
+ uint i, j;
+
+/***********************************************************************/
+/* */
+/* Create two files containing identical datasets. Write 0's to one */
+/* and 1's to the other. */
+/* */
+/***********************************************************************/
+
+ for ( i = 0; i &lt DIM1; i++ )
+ for ( j = 0; j &lt DIM2; j++ )
+ buf1[i][j] = 0;
+
+ for ( i = 0; i &lt DIM1; i++ )
+ for ( j = 0; j &lt DIM2; j++ )
+ buf2[i][j] = 1;
+
+ file1 = H5Fcreate(FILE1, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+ file2 = H5Fcreate(FILE2, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
+
+ fid1 = H5Screate_simple (RANK, fdim, NULL);
+ fid2 = H5Screate_simple (RANK, fdim, NULL);
+
+ dataset1 = H5Dcreate (file1, "Copy1", H5T_NATIVE_INT, fid1, H5P_DEFAULT);
+ dataset2 = H5Dcreate (file2, "Copy2", H5T_NATIVE_INT, fid2, H5P_DEFAULT);
+
+ ret = H5Dwrite(dataset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf1);
+ ret = H5Dwrite(dataset2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, buf2);
+
+ ret = H5Dclose (dataset1);
+ ret = H5Dclose (dataset2);
+
+ ret = H5Sclose (fid1);
+ ret = H5Sclose (fid2);
+
+ ret = H5Fclose (file1);
+ ret = H5Fclose (file2);
+
+/***********************************************************************/
+/* */
+/* Open the two files. Select two points in one file, write values to */
+/* those point locations, then do H5Scopy and write the values to the */
+/* other file. Close files. */
+/* */
+/***********************************************************************/
+
+ file1 = H5Fopen (FILE1, H5F_ACC_RDWR, H5P_DEFAULT);
+ file2 = H5Fopen (FILE2, H5F_ACC_RDWR, H5P_DEFAULT);
+ dataset1 = H5Dopen (file1, "Copy1");
+ dataset2 = H5Dopen (file2, "Copy2");
+ fid1 = H5Dget_space (dataset1);
+ mid1 = H5Screate_simple(1, marray, NULL);
+ coord[0][0] = 0; coord[0][1] = 3;
+ coord[1][0] = 0; coord[1][1] = 1;
+
+ ret = H5Sselect_elements (fid1, H5S_SELECT_SET, NUMP, (const hssize_t **)coord);
+
+ ret = H5Dwrite (dataset1, H5T_NATIVE_INT, mid1, fid1, H5P_DEFAULT, val);
+
+ fid2 = H5Scopy (fid1);
+
+ ret = H5Dwrite (dataset2, H5T_NATIVE_INT, mid1, fid2, H5P_DEFAULT, val);
+
+ ret = H5Dclose (dataset1);
+ ret = H5Dclose (dataset2);
+ ret = H5Sclose (fid1);
+ ret = H5Sclose (fid2);
+ ret = H5Fclose (file1);
+ ret = H5Fclose (file2);
+ ret = H5Sclose (mid1);
+
+/***********************************************************************/
+/* */
+/* Open both files and print the contents of the datasets. */
+/* */
+/***********************************************************************/
+
+ file1 = H5Fopen (FILE1, H5F_ACC_RDWR, H5P_DEFAULT);
+ file2 = H5Fopen (FILE2, H5F_ACC_RDWR, H5P_DEFAULT);
+ dataset1 = H5Dopen (file1, "Copy1");
+ dataset2 = H5Dopen (file2, "Copy2");
+
+ ret = H5Dread (dataset1, H5T_NATIVE_INT, H5S_ALL, H5S_ALL,
+ H5P_DEFAULT, bufnew);
+
+ printf ("\nDataset 'Copy1' in file 'copy1.h5' contains: \n");
+ for (i=0;i&lt;DIM1; i++) {
+ for (j=0;j&lt;DIM2;j++) printf ("%3d ", bufnew[i][j]);
+ printf("\n");
+ }
+
+ printf ("\nDataset 'Copy2' in file 'copy2.h5' contains: \n");
+
+ ret = H5Dread (dataset2, H5T_NATIVE_INT, H5S_ALL, H5S_ALL,
+ H5P_DEFAULT, bufnew);
+
+ for (i=0;i&lt;DIM1; i++) {
+ for (j=0;j&lt;DIM2;j++) printf ("%3d ", bufnew[i][j]);
+ printf("\n");
+ }
+ ret = H5Dclose (dataset1);
+ ret = H5Dclose (dataset2);
+ ret = H5Fclose (file1);
+ ret = H5Fclose (file2);
+
+}
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+</PRE>
+
+<A NAME="rem">
+<H3><U>Remarks</U></H3>
+<UL>
+<LI>H5Sselect_elements selects array elements to be included in the
+selection for a dataspace:
+<PRE>
+ herr_t H5Sselect_elements (hid_t space_id, H5S_seloper_t op,
+ size_t num_elem, const hssize_t **coord )
+</PRE>
+<UL>
+<LI>The <I>space_id</I> parameter is the dataspace identifier.<BR>
+<LI>The <I>op</I> parameter currently can only be set to H5S_SELECT_SET and
+specifies to replace the existing selection with the parameters from this
+call.
+<LI>The <I>coord</I> array is a two-dimensional array of size 'dataspace rank'
+by the number of elements to be selected, <I>num_elem</I>.<BR>
+</UL>
+<P>
+<LI>H5Scopy creates an exact copy of a dataspace:
+<PRE>
+ hid_t H5Scopy(hid_t space_id )
+</PRE>
+<UL>
+<LI>The <I>space_id</I> parameter is the dataspace identifier to copy.
+</UL>
+</UL>
+</UL>
+<P>
+
+<A NAME="fc">
+<H3><U>File Contents</U></H3>
+
+Following is the DDL for <I>copy1.h5</I> and <I>copy2.h5</I>, as viewed with
+the commands "h5dump copy1.h5" and "h5dump copy2.h5".
+<P>
+<B>Fig. S.1</B> &nbsp; <I>'copy1.h5' in DDL</I>
+<PRE>
+HDF5 "copy1.h5" {
+GROUP "/" {
+ DATASET "Copy1" {
+ DATATYPE { H5T_STD_I32BE }
+ DATASPACE { SIMPLE ( 3, 4 ) / ( 3, 4 ) }
+ DATA {
+ 0, 59, 0, 53,
+ 0, 0, 0, 0,
+ 0, 0, 0, 0
+ }
+ }
+}
+}
+</PRE>
+<B>Fig. S.2</B> &nbsp; <I>'copy2.h5' in DDL</I>
+<PRE>
+HDF5 "copy2.h5" {
+GROUP "/" {
+ DATASET "Copy2" {
+ DATATYPE { H5T_STD_I32BE }
+ DATASPACE { SIMPLE ( 3, 4 ) / ( 3, 4 ) }
+ DATA {
+ 1, 59, 1, 53,
+ 1, 1, 1, 1,
+ 1, 1, 1, 1
+ }
+ }
+}
+}
+
+</PRE>
+
+
+
+<!-- BEGIN FOOTER INFO -->
+
+<P><hr noshade size=1>
+<font face="arial,helvetica" size="-1">
+ <a href="http://www.ncsa.uiuc.edu/"><img border=0
+ src="http://www.ncsa.uiuc.edu/Images/NCSAhome/footerlogo.gif"
+ width=78 height=27 alt="NCSA"><br>
+ The National Center for Supercomputing Applications</A><br>
+ <a href="http://www.uiuc.edu/">University of Illinois
+ at Urbana-Champaign</a><br>
+ <br>
+<!-- <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>
+<!-- modified by Barbara Jones - bljones@ncsa.uiuc.edu -->
+</FONT>
+<BR>
+<!-- <A HREF="mailto:hdfhelp@ncsa.uiuc.edu"> -->
+
+</BODY>
+</HTML>
+
+
+