hdf5/c++/examples/h5tutr_subset.cpp
Binh-Minh Ribler 8597110837 [svn-r24235] Description:
- Appended h5tutr_ to names of data files to avoid name clashing with
      existing examples.
    - Added example dependencies to Makefile.*
    (pointed out by Allen)

Platforms tested:
    SunOS 5.11 (emu) with gmake
    Linux/ppc64 (ostrich)
    Linux/32 2.6 (jam)
    Linux/64 2.6 (koala)/PGI compilers
2013-09-30 21:40:32 -05:00

184 lines
5.0 KiB
C++

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* Copyright by The HDF Group. *
* Copyright by the Board of Trustees of the University of Illinois. *
* All rights reserved. *
* *
* This file is part of HDF5. The full HDF5 copyright notice, including *
* terms governing use, modification, and redistribution, is contained in *
* the files COPYING and Copyright.html. COPYING can be found at the root *
* of the source code distribution tree; Copyright.html can be found at the *
* root level of an installed copy of the electronic HDF5 document set and *
* is linked from the top-level documents page. It can also be found at *
* http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have *
* access to either file, you may request a copy from help@hdfgroup.org. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/*
* This example illustrates how to read/write a subset of data (a slab)
* from/to a dataset in an HDF5 file. It is used in the HDF5 Tutorial.
*/
#include <iostream>
#include <string>
#include "H5Cpp.h"
#ifndef H5_NO_NAMESPACE
using namespace H5;
#ifndef H5_NO_STD
using std::cout;
using std::endl;
#endif // H5_NO_STD
#endif
const H5std_string FILE_NAME("h5tutr_subset.h5");
const H5std_string DATASET_NAME("IntArray");
const int RANK = 2;
const int DIM0_SUB = 3; // subset dimensions
const int DIM1_SUB = 4;
const int DIM0 = 8; // size of dataset
const int DIM1 = 10;
int main (void)
{
int i,j;
int data[DIM0][DIM1], sdata[DIM0_SUB][DIM1_SUB], rdata[DIM0][DIM1];
// Try block to detect exceptions raised by any of the calls inside it
try
{
// Turn off the auto-printing when failure occurs so that we can
// handle the errors appropriately
Exception::dontPrint();
// ---------------------------------------------------
// Create a new file using the default property lists.
// Then create a dataset and write data to it.
// Close the file and dataset.
// ---------------------------------------------------
H5File file(FILE_NAME, H5F_ACC_TRUNC);
hsize_t dims[2];
dims[0] = DIM0;
dims[1] = DIM1;
DataSpace dataspace = DataSpace (RANK, dims);
DataSet dataset(file.createDataSet( DATASET_NAME,
PredType::STD_I32BE, dataspace) );
for (j = 0; j < DIM0; j++) {
for (i = 0; i < DIM1; i++)
if (i< (DIM1/2))
data[j][i] = 1;
else
data[j][i] = 2;
}
dataset.write(data, PredType::NATIVE_INT);
cout << endl << "Data Written to File:" << endl;
for (j = 0; j < DIM0; j++) {
for (i = 0; i < DIM1; i++)
cout << " " << data[j][i];
cout << endl;
}
dataspace.close();
dataset.close();
file.close();
// ---------------------------------------------------
// Reopen the file and dataset and write a subset of
// values to the dataset.
// ---------------------------------------------------
hsize_t offset[2], count[2], stride[2], block[2];
hsize_t dimsm[2];
file.openFile(FILE_NAME, H5F_ACC_RDWR);
dataset = file.openDataSet(DATASET_NAME);
// Specify size and shape of subset to write.
offset[0] = 1;
offset[1] = 2;
count[0] = DIM0_SUB;
count[1] = DIM1_SUB;
stride[0] = 1;
stride[1] = 1;
block[0] = 1;
block[1] = 1;
// Define Memory Dataspace. Get file dataspace and select
// a subset from the file dataspace.
dimsm[0] = DIM0_SUB;
dimsm[1] = DIM1_SUB;
DataSpace memspace(RANK, dimsm, NULL);
dataspace = dataset.getSpace();
dataspace.selectHyperslab(H5S_SELECT_SET, count, offset, stride, block);
// Write a subset of data to the dataset, then read the
// entire dataset back from the file.
cout << endl << "Write subset to file specifying: " << endl;
cout << " offset=1x2 stride=1x1 count=3x4 block=1x1" << endl;
for (j = 0; j < DIM0_SUB; j++) {
for (i = 0; i < DIM1_SUB; i++)
sdata[j][i] = 5;
}
dataset.write(sdata, PredType::NATIVE_INT, memspace, dataspace);
dataset.read(rdata, PredType::NATIVE_INT);
cout << endl << "Data in File after Subset is Written:" << endl;
for (i = 0; i < DIM0; i++) {
for (j = 0; j < DIM1; j++)
cout << " " << rdata[i][j];
cout << endl;
}
cout << endl;
// It is not necessary to close these objects because close() will
// be called when the object instances are going out of scope.
dataspace.close();
memspace.close();
dataset.close();
file.close();
} // end of try block
// catch failure caused by the H5File operations
catch(FileIException error)
{
error.printError();
return -1;
}
// catch failure caused by the DataSet operations
catch(DataSetIException error)
{
error.printError();
return -1;
}
// catch failure caused by the DataSpace operations
catch(DataSpaceIException error)
{
error.printError();
return -1;
}
return 0; // successfully terminated
}