[svn-r3088] Renamed writedata.C to writedata.cpp

1 files changed, 227 insertions, 0 deletions

diff --git a/c++/examples/writedata.cpp b/c++/examples/writedata.cpp
new file mode 100644
index 0000000..8179113
--- /dev/null
+++ b/c++/examples/writedata.cpp
@@ -0,0 +1,227 @@
+/* 
+ *  This program shows how the select_hyperslab and select_elements
+ *  functions are used to write selected data from memory to the file.
+ *  Program takes 48 elements from the linear buffer and writes them into
+ *  the matrix using 3x2 blocks, (4,3) stride and (2,4) count. 
+ *  Then four elements  of the matrix are overwritten with the new values and 
+ *  file is closed. Program reopens the file and reads and displays the result.
+ */ 
+ 
+#include <string>
+#ifndef H5_NO_NAMESPACE
+using namespace std;
+#endif
+
+#ifdef OLD_HEADER_FILENAME
+#include <iostream.h>
+#else
+#include <iostream>
+#endif
+#include "H5Cpp.h"
+ 
+#ifndef H5_NO_NAMESPACE
+using namespace H5;
+#endif
+
+const string FILE_NAME( "Select.h5" );
+const string DATASET_NAME( "Matrix in file" );
+const int   MSPACE1_RANK = 1;	// Rank of the first dataset in memory
+const int   MSPACE1_DIM = 50;   // Dataset size in memory
+const int   MSPACE2_RANK = 1;	// Rank of the second dataset in memory
+const int   MSPACE2_DIM = 4;	// Dataset size in memory
+const int   FSPACE_RANK = 2;	// Dataset rank as it is stored in the file
+const int   FSPACE_DIM1 = 8;	// Dimension sizes of the dataset as it is...
+const int   FSPACE_DIM2 = 12;	// ...stored in the file 
+const int   MSPACE_DIM1 = 8;	// We will read dataset back from the file...
+const int   MSPACE_DIM2 = 12;	// ...to the dataset in memory with these ...
+				// ...dataspace parameters
+const int   NPOINTS = 4;	// Number of points that will be selected...
+                                //    ...and overwritten
+
+int main (void)
+{
+   /*
+   * Buffers' initialization.
+   */
+   uint   i,j;
+   int    vector[MSPACE1_DIM];
+   vector[0] = vector[MSPACE1_DIM - 1] = -1;
+   for (i = 1; i < MSPACE1_DIM - 1; i++)
+      vector[i] = i;
+
+   int    matrix[MSPACE_DIM1][MSPACE_DIM2];
+   for (i = 0; i < MSPACE_DIM1; i++)
+   {
+      for (j = 0; j < MSPACE_DIM2; j++)
+	 matrix[i][j] = 0;
+   }
+
+   // Try block to detect exceptions raised by any of the calls inside it
+   try
+   {
+      //
+      //Create a file.
+      //
+      H5File* file = new H5File( FILE_NAME, H5F_ACC_TRUNC );
+
+      // 
+      //Create dataspace for the dataset in the file.
+      //
+      hsize_t fdim[] = {FSPACE_DIM1, FSPACE_DIM2}; // dim sizes of ds (on disk)
+      DataSpace fspace( FSPACE_RANK, fdim );
+
+      //
+      // Create dataset and write it into the file.
+      //
+      DataSet* dataset = new DataSet( 
+            file->createDataSet( DATASET_NAME, PredType::NATIVE_INT, fspace ));
+      dataset->write( matrix, PredType::NATIVE_INT );
+
+      //
+      // Select hyperslab for the dataset in the file, using 3x2 blocks, 
+      // (4,3) stride and (2,4) count starting at the position (0,1).
+      //
+      hssize_t start[2]; // Start of hyperslab
+      hsize_t stride[2]; // Stride of hyperslab
+      hsize_t count[2];  // Block count
+      hsize_t block[2];  // Block sizes
+      start[0]  = 0; start[1]  = 1;
+      stride[0] = 4; stride[1] = 3;
+      count[0]  = 2; count[1]  = 4;    
+      block[0]  = 3; block[1]  = 2;
+      fspace.selectHyperslab( H5S_SELECT_SET, count, start, stride, block);
+
+      //
+      // Create dataspace for the first dataset.
+      //
+      hsize_t dim1[] = {MSPACE1_DIM};  /* Dimension size of the first dataset 
+                                         (in memory) */ 
+      DataSpace mspace1( MSPACE1_RANK, dim1 );
+
+      /*
+       * Select hyperslab. 
+       * We will use 48 elements of the vector buffer starting at the 
+       * second element.  Selected elements are 1 2 3 . . . 48
+       */
+      start[0]  = 1;
+      stride[0] = 1;
+      count[0]  = 48;
+      block[0]  = 1;
+      mspace1.selectHyperslab( H5S_SELECT_SET, count, start, stride, block);
+ 
+      /*
+       * Write selection from the vector buffer to the dataset in the file.
+       *
+       * File dataset should look like this:       
+       *                    0  1  2  0  3  4  0  5  6  0  7  8 
+       *                    0  9 10  0 11 12  0 13 14  0 15 16
+       *                    0 17 18  0 19 20  0 21 22  0 23 24
+       *                    0  0  0  0  0  0  0  0  0  0  0  0
+       *                    0 25 26  0 27 28  0 29 30  0 31 32
+       *                    0 33 34  0 35 36  0 37 38  0 39 40
+       *                    0 41 42  0 43 44  0 45 46  0 47 48
+       *                    0  0  0  0  0  0  0  0  0  0  0  0
+       */
+       dataset->write( vector, PredType::NATIVE_INT, mspace1, fspace );
+
+      /*
+       * Reset the selection for the file dataspace fid.
+       */
+      fspace.selectNone();
+
+      /*
+       * Create dataspace for the second dataset.
+       */
+      hsize_t dim2[] = {MSPACE2_DIM};  /* Dimension size of the second dataset
+                                         (in memory */ 
+      DataSpace mspace2( MSPACE2_RANK, dim2 );
+
+      /*
+       * Select sequence of NPOINTS points in the file dataspace.
+       */
+      hssize_t coord[NPOINTS][FSPACE_RANK]; /* Array to store selected points 
+                                              from the file dataspace */ 
+      coord[0][0] = 0; coord[0][1] = 0;
+      coord[1][0] = 3; coord[1][1] = 3;
+      coord[2][0] = 3; coord[2][1] = 5;
+      coord[3][0] = 5; coord[3][1] = 6;
+
+      fspace.selectElements( H5S_SELECT_SET, NPOINTS, (const hssize_t **)coord);
+
+      /*
+       * Write new selection of points to the dataset.
+       */
+      int    values[] = {53, 59, 61, 67};  /* New values to be written */
+      dataset->write( values, PredType::NATIVE_INT, mspace2, fspace );   
+
+      /*
+       * File dataset should look like this:     
+       *                   53  1  2  0  3  4  0  5  6  0  7  8 
+       *                    0  9 10  0 11 12  0 13 14  0 15 16
+       *                    0 17 18  0 19 20  0 21 22  0 23 24
+       *                    0  0  0 59  0 61  0  0  0  0  0  0
+       *                    0 25 26  0 27 28  0 29 30  0 31 32
+       *                    0 33 34  0 35 36 67 37 38  0 39 40
+       *                    0 41 42  0 43 44  0 45 46  0 47 48
+       *                    0  0  0  0  0  0  0  0  0  0  0  0
+       *                                        
+       */
+
+      /*
+       * Close the dataset and the file.
+       */
+      delete dataset;
+      delete file;
+
+      /*
+       * Open the file.
+       */
+      file = new H5File( FILE_NAME, H5F_ACC_RDONLY );
+
+      /*
+       * Open the dataset.
+       */
+      dataset = new DataSet( file->openDataSet( DATASET_NAME ));
+
+      /*
+       * Read data back to the buffer matrix.
+       */
+      dataset->read( matrix, PredType::NATIVE_INT );
+
+      /*
+       * Display the result.
+       */
+      for (i=0; i < MSPACE_DIM1; i++)
+      {
+          for(j=0; j < MSPACE_DIM2; j++)
+	     cout << matrix[i][j] << "  ";
+          cout << endl;
+      }
+
+      /*
+       * Close the dataset and the file.
+       */
+      delete dataset;
+      delete file;
+   }  // end of try block
+
+   // catch failure caused by the H5File operations
+   catch( FileIException error )
+   {
+      error.printError();
+   }
+
+   // catch failure caused by the DataSet operations
+   catch( DataSetIException error )
+   {
+      error.printError();
+   }
+
+   // catch failure caused by the DataSpace operations
+   catch( DataSpaceIException error )
+   {
+      error.printError();
+   }
+
+   return 0;
+}