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
224
225
226
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;
}
|
