ex_lite1.c

在雷达遥感等方面应用的hdf5数据格式的编程源代码

/****************************************************************************
* NCSA HDF                                                                 *
* Scientific Data Technologies                                             *
* National Center for Supercomputing Applications                          *
* University of Illinois at Urbana-Champaign                               *
* 605 E. Springfield, Champaign IL 61820                                   *
*                                                                          *
* For conditions of distribution and use, see the accompanying             *
* hdf/COPYING f.                                                           *
*                                                                          *
****************************************************************************/

 
#include "H5LT.h"
#include "math.h"

#define DATA_SIZE 1000000
typedef struct {
	double re; /*real part*/
	double im; /*imaginary part*/
} complex_t;

complex_t    data[DATA_SIZE];
int  data1[DATA_SIZE];
int main( void )
{

	hid_t       file_id; 
	hid_t group1,group2;
	hsize_t     dims[1];
	herr_t      status;
	int i,j;
	char dset_name[100];
	double attr_test[3]={1234.56789,1,2.3};
	char str_data[256];
	hid_t complex_id;

	//压缩试验而定义的变量
	hid_t  data_space, dataset32, properties;
	unsigned szip_options_mask;
	unsigned szip_pixels_per_block;
	hsize_t chunk_size[2];



	EXAMPLE("make a dataset");   //EXAMPLE  在H5LT.h 中定义，将字符输出

	file_id = H5Fcreate ("h:\\ex_lite2.h5", H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); 

	



	group1=H5Gcreate(file_id,"/Group1",0);
	group2=H5Gcreate(file_id,"/Group2",0);

	//创建自定义的结构
	complex_id = H5Tcreate (H5T_COMPOUND, sizeof(complex_t));
	H5Tinsert (complex_id, "real", HOFFSET(complex_t,re),
		H5T_NATIVE_DOUBLE);
	H5Tinsert (complex_id, "imaginary", HOFFSET(complex_t,im),
		H5T_NATIVE_DOUBLE);

	for (j=0;j<DATA_SIZE;j++)
	{
		data1[j]=rand();
	}

	for (i=0;i<10000;i++)
	{
		sprintf(dset_name,"dset%.8d",i);
		printf("%s\n",dset_name);

		/*for (j=0;j<DATA_SIZE;j++)
		{
			data[j].im=i*i+j;
			data[j].re=i*i+j-1;
			data1[j]=rand();
		}  //*/

		dims[0] =10;// DATA_SIZE;
		status = H5LTmake_dataset(group1,dset_name,1,dims,H5T_NATIVE_INT,data1);

		H5LTset_attribute_double(group1,dset_name,"Samplefreq",attr_test,3);
		H5LTset_attribute_string(group1,dset_name,"Note","this is a test. 这是一个例子");


		H5LTget_attribute_string(group1,dset_name,"Note",str_data);
		printf("%s",str_data);

		dims[0] = DATA_SIZE;
		//试验压缩
		data_space = H5Screate_simple (1, dims, NULL);

		chunk_size[0] = 10000;
		//chunk_size[1] = CH_25;
		properties = H5Pcreate (H5P_DATASET_CREATE);
		
		H5Pset_chunk (properties, 1, chunk_size);


		/* 
		* Set parameters for SZIP compression; check the description of
		* the H5Pset_szip function in the HDF5 Reference Manual for more 
		* information.
		*/
		szip_options_mask=H5_SZIP_NN_OPTION_MASK;
		szip_pixels_per_block=32;

		H5Pset_szip (properties, szip_options_mask, szip_pixels_per_block);

		dataset32=H5Dcreate(group2,dset_name,H5T_NATIVE_INT,data_space, properties);
		H5Dwrite (dataset32, H5T_NATIVE_INT, H5S_ALL, H5S_ALL,H5P_DEFAULT, data1);
	
		H5Dclose (dataset32);
		H5Sclose (data_space);
		H5Pclose (properties);


	}


	H5Tclose(complex_id);
	H5Gclose(group1);
	H5Gclose(group2);
	status = H5Fclose (file_id);    

	PASSED();                        //PASSED 在H5LT.h 中定义，输出"Passed"
	getchar();

	return 0;


}