summaryrefslogtreecommitdiffstats
path: root/c++/examples/compound.cpp
blob: 994a036a6a1b3e02b5e867c82032ebec67a50329 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * 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://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
 * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * This example shows how to create a compound datatype,
 * write an array which has the compound datatype to the file,
 * and read back fields' subsets.
 */

#ifdef OLD_HEADER_FILENAME
#include <iostream.h>
#else
#include <iostream>
#endif
#include <string>

#ifndef H5_NO_NAMESPACE
#ifndef H5_NO_STD
    using std::cout;
    using std::endl;
#endif  // H5_NO_STD
#endif

#include "H5Cpp.h"

#ifndef H5_NO_NAMESPACE
    using namespace H5;
    using H5_std::string;
#endif

const string FILE_NAME( "SDScompound.h5" );
const string DATASET_NAME( "ArrayOfStructures" );
const string MEMBER1( "a_name" );
const string MEMBER2( "b_name" );
const string MEMBER3( "c_name" );
const int   LENGTH = 10;
const int   RANK = 1;

int main(void)
{
   /* First structure  and dataset*/
   typedef struct s1_t {
	int      a;
	float  b;
	double c;
   } s1_t;

   /* Second structure (subset of s1_t)  and dataset*/
   typedef struct s2_t {
	double c;
	int      a;
   } s2_t;

   // Try block to detect exceptions raised by any of the calls inside it
   try
   {
      /*
       * Initialize the data
       */
      int        i;
      s1_t       s1[LENGTH];
      for (i = 0; i< LENGTH; i++)
      {
         s1[i].a = i;
         s1[i].b = i*i;
         s1[i].c = 1./(i+1);
      }

      /*
       * Turn off the auto-printing when failure occurs so that we can
       * handle the errors appropriately
       */
      Exception::dontPrint();

      /*
       * Create the data space.
       */
      hsize_t    dim[] = {LENGTH};   /* Dataspace dimensions */
      DataSpace space( RANK, dim );

      /*
       * Create the file.
       */
      H5File* file = new H5File( FILE_NAME, H5F_ACC_TRUNC );

      /*
       * Create the memory datatype.
       */
      CompType mtype1( sizeof(s1_t) );
      mtype1.insertMember( MEMBER1, HOFFSET(s1_t, a), PredType::NATIVE_INT);
      mtype1.insertMember( MEMBER3, HOFFSET(s1_t, c), PredType::NATIVE_DOUBLE);
      mtype1.insertMember( MEMBER2, HOFFSET(s1_t, b), PredType::NATIVE_FLOAT);

      /*
       * Create the dataset.
       */
      DataSet* dataset;
      dataset = new DataSet( file->createDataSet( DATASET_NAME, mtype1, space ));

      /*
       * Wtite data to the dataset;
       */
      dataset->write( s1, mtype1 );

      /*
       * Release resources
       */
      delete dataset;
      delete file;

      // Get the class of the first member in mtype1, then get its type
      H5T_class_t member1_class = mtype1.getMemberClass( 2 );
      if( member1_class == H5T_FLOAT )
      {
	 FloatType member2 = mtype1.getMemberFloatType( 2 );
	 string norm_string;
	 H5T_norm_t norm = member2.getNorm( norm_string );
	 cout << "Normalization type is " << norm_string << endl;
      }

      /*
       * Open the file and the dataset.
       */
      file = new H5File( FILE_NAME, H5F_ACC_RDONLY );
      dataset = new DataSet (file->openDataSet( DATASET_NAME ));

      /*
       * Create a datatype for s2
       */
      CompType mtype2( sizeof(s2_t) );

      mtype2.insertMember( MEMBER3, HOFFSET(s2_t, c), PredType::NATIVE_DOUBLE);
      mtype2.insertMember( MEMBER1, HOFFSET(s2_t, a), PredType::NATIVE_INT);

      /*
       * Read two fields c and a from s1 dataset. Fields in the file
       * are found by their names "c_name" and "a_name".
       */
      s2_t       s2[LENGTH];
      dataset->read( s2, mtype2 );

      /*
       * Display the fields
       */
      cout << endl << "Field c : " << endl;
      for( i = 0; i < LENGTH; i++)
	 cout << s2[i].c << " ";
      cout << endl;

      cout << endl << "Field a : " << endl;
      for( i = 0; i < LENGTH; i++)
	 cout << s2[i].a << " ";
      cout << endl;

      /*
       * Create a datatype for s3.
       */
      CompType mtype3( sizeof(float) );

      mtype3.insertMember( MEMBER2, 0, PredType::NATIVE_FLOAT);

      /*
       * Read field b from s1 dataset. Field in the file is found by its name.
       */
      float s3[LENGTH];  // Third "structure" - used to read float field of s1)
      dataset->read( s3, mtype3 );

      /*
       * Display the field
       */
      cout << endl << "Field b : " << endl;
      for( i = 0; i < LENGTH; i++)
	 cout << s3[i] << " ";
      cout << endl;

      /*
       * Release resources
       */
      delete dataset;
      delete file;
   }  // 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;
   }

   // catch failure caused by the DataSpace operations
   catch( DataTypeIException error )
   {
      error.printError();
      return -1;
   }

   return 0;
}