/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Copyright by The HDF Group. * * 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 COPYING file, which can be found at the root of the source code * * distribution tree, or in https://www.hdfgroup.org/licenses. * * If you do not have access to either file, you may request a copy from * * help@hdfgroup.org. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ /* * This example demonstrates how the data transform features of * HDF5 works. * * (1) * The test first writes out data, with no data transform set. * Then, the test reads back this data with a data transform applied. * * (2) * Then, the test writes a new set of data, with a data transform set. * Then, the test reads this new set of data, without a data set. * * (3) * Lastly, the test reads the previous set of data (that was written out * with a data transform) with a data transform set for the read. * * (4) * Get the transform from the property using H5Pget_data_transform. */ #include "hdf5.h" #define ROWS 12 #define COLS 18 /* clang-format off */ const float windchillF[ROWS][COLS] = { {36.0, 31.0, 25.0, 19.0, 13.0, 7.0, 1.0, -5.0, -11.0, -16.0, -22.0, -28.0, -34.0, -40.0, -46.0, -52.0, -57.0, -63.0}, {34.0, 27.0, 21.0, 15.0, 9.0, 3.0, -4.0, -10.0, -16.0, -22.0, -28.0, -35.0, -41.0, -47.0, -53.0, -59.0, -66.0, -72.0}, {32.0, 25.0, 19.0, 13.0, 6.0, 0.0, -7.0, -13.0, -19.0, -26.0, -32.0, -39.0, -45.0, -51.0, -58.0, -64.0, -71.0, -77.0}, {30.0, 24.0, 17.0, 11.0, 4.0, -2.0, -9.0, -15.0, -22.0, -29.0, -35.0, -42.0, -48.0, -55.0, -61.0, -68.0, -74.0, -81.0}, {29.0, 23.0, 16.0, 9.0, 3.0, -4.0, -11.0, -17.0, -24.0, -31.0, -37.0, -44.0, -51.0, -58.0, -64.0, -71.0, -78.0, -84.0}, {28.0, 22.0, 15.0, 8.0, 1.0, -5.0, -12.0, -19.0, -26.0, -33.0, -39.0, -46.0, -53.0, -60.0, -67.0, -73.0, -80.0, -87.0}, {28.0, 21.0, 14.0, 7.0, 0.0, -7.0, -14.0, -21.0, -27.0, -34.0, -41.0, -48.0, -55.0, -62.0, -69.0, -76.0, -82.0, -89.0}, {27.0, 20.0, 13.0, 6.0, -1.0, -8.0, -15.0, -22.0, -29.0, -36.0, -43.0, -50.0, -57.0, -64.0, -71.0, -78.0, -84.0, -91.0}, {26.0, 19.0, 12.0, 5.0, -2.0, -9.0, -16.0, -23.0, -30.0, -37.0, -44.0, -51.0, -58.0, -65.0, -72.0, -79.0, -86.0, -93.0}, {26.0, 19.0, 12.0, 4.0, -3.0, -10.0, -17.0, -24.0, -31.0, -38.0, -45.0, -52.0, -60.0, -67.0, -74.0, -81.0, -88.0, -95.0}, {25.0, 18.0, 11.0, 4.0, -3.0, -11.0, -18.0, -25.0, -32.0, -39.0, -46.0, -54.0, -61.0, -68.0, -75.0, -82.0, -89.0, -97.0}, {25.0, 17.0, 10.0, 3.0, -4.0, -11.0, -19.0, -26.0, -33.0, -40.0, -48.0, -55.0, -62.0, -69.0, -76.0, -84.0, -91.0, -98.0} }; /* clang-format on */ #define PRINT(array) \ { \ for (i = 0; i < ROWS; i++) { \ for (j = 0; j < COLS; j++) \ printf("%6.2f ", array[i][j]); \ printf("\n"); \ } \ } int main(void) { hid_t file, dataset; /* file and dataset handles */ hid_t dataspace; /* handles */ hsize_t dimsf[2]; /* dataset dimensions */ herr_t status; hid_t dxpl_id_f_to_c, dxpl_id_c_to_f; /* data transform handles */ const char *f_to_c = "(5/9.0)*(x-32)"; const char *c_to_f = "(9/5.0)*x + 32"; char *transform; float windchillC[ROWS][COLS]; int i, j, transform_size; /* * Create a new file using H5F_ACC_TRUNC access, * default file creation properties, and default file * access properties. */ file = H5Fcreate("dtransform.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); /* * Describe the size of the array and create the data space for fixed * size dataset. */ dimsf[0] = ROWS; dimsf[1] = COLS; dataspace = H5Screate_simple(2, dimsf, NULL); /* * Create a new dataset within the file using defined dataspace and * datatype and default dataset creation properties. */ dataset = H5Dcreate2(file, "data_no_trans", H5T_NATIVE_FLOAT, dataspace, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); printf("\nOriginal Data: \n"); PRINT(windchillF); /**************** PART 1 **************/ /* * Write the data to the dataset using default transfer properties (ie, no transform set) */ status = H5Dwrite(dataset, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, H5P_DEFAULT, windchillF); /* Create the dataset transfer property list */ dxpl_id_f_to_c = H5Pcreate(H5P_DATASET_XFER); /* Set the data transform */ H5Pset_data_transform(dxpl_id_f_to_c, f_to_c); /* Read out the data with the data transform */ H5Dread(dataset, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, dxpl_id_f_to_c, windchillC); /* Print the data from the read*/ printf("\nData with no write transform, but a read transform: \n"); PRINT(windchillC); /**************** PART 2 **************/ /* * Write the data to the dataset with the f_to_c transform set */ status = H5Dwrite(dataset, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, dxpl_id_f_to_c, windchillF); /* Read out the data with the default transfer list (ie, no transform set) */ H5Dread(dataset, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, H5P_DEFAULT, windchillC); /* Print the data from the read*/ printf("\nData with write transform, but no read transform: \n"); PRINT(windchillC); /************** PART 3 ***************/ /* Create the dataset transfer property list */ dxpl_id_c_to_f = H5Pcreate(H5P_DATASET_XFER); /* Set the data transform to be used on the read*/ H5Pset_data_transform(dxpl_id_c_to_f, c_to_f); /* * Write the data to the dataset using the f_to_c transform */ status = H5Dwrite(dataset, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, dxpl_id_f_to_c, windchillF); /* Read the data with the c_to_f data transform */ H5Dread(dataset, H5T_NATIVE_FLOAT, H5S_ALL, H5S_ALL, dxpl_id_c_to_f, windchillC); /* Print the data from the read*/ printf("\nData with both read and write data transform: \n"); PRINT(windchillC); /************** PART 4 **************/ transform_size = H5Pget_data_transform(dxpl_id_f_to_c, NULL, 0); transform = (char *)malloc(transform_size + 1); H5Pget_data_transform(dxpl_id_f_to_c, transform, transform_size + 1); printf("\nTransform string (from dxpl_id_f_to_c) is: %s\n", transform); /* * Close/release resources. */ H5Pclose(dxpl_id_c_to_f); H5Pclose(dxpl_id_f_to_c); H5Sclose(dataspace); H5Dclose(dataset); H5Fclose(file); return 0; }