Hi HDF5-users,
I have a specific question on - how to identify a specific datatype of a dataset, based on which you could allocate memory and store the data read from HDF5 file.
Supposedly, i store few datasets as given below -
const int dims0 = 1;
const int RANK0 = 1;
const int dims1 = 3;
const int RANK1 = 1;
const int dims21 = 2;
const int dims22 = 3;
const int RANK2 = 2;
//WRITING DATA on DATASET
hsize_t dimsf0[]={dims0};
hsize_t dimsf1[]={dims1};
hsize_t dimsf2[]={dims21,dims22};
H5File file( FILE_NAME, H5F_ACC_TRUNC );
DataSpace sid0(RANK0, dimsf0);
DataSpace sid1(RANK1, dimsf1);
DataSpace sid2(RANK2, dimsf2);
StrType strdatatype(PredType::C_S1, 100);
Attribute a_s=dataset.createAttribute("at_string1",strdatatype,sid0);
a_s.write(strdatatype,"This is the value for string attribute");
// Create integer attribute and add to dataset
int d0[dims0]={10};
float d2[dims21][dims22]={{11.1,21.1,32.2},{31.1,41.1,72.2}};
double d4[dims21][dims22]={{11.1,21.1,32.2},{31.1,41.1,72.2}};
char d3[dims21][dims22]={{'3','4','5'},{'6','7','8'}};
Group G2 = G1.createGroup("G2-GROUP");
dataset = G2.createDataSet("ds_int2_group", PredType::NATIVE_INT, sid0);
dataset.write(d0, PredType::NATIVE_INT);
dataset = G2.createDataSet("ds_float2_group", PredType::NATIVE_FLOAT, sid2);
dataset.write((void*)d2, PredType::NATIVE_FLOAT);
dataset = G2.createDataSet("ds_float2_group", PredType::NATIVE_DOUBLE, sid2);
dataset.write((void*)d4, PredType::NATIVE_DOUBLE);
dataset = G2.createDataSet("ds_char_group", PredType::NATIVE_CHAR, sid2);
dataset.write((void*)d3, PredType::NATIVE_CHAR);
//READING DATA from DATASET
StrType tid1(0, H5T_STRING);
dataset=nfile.openDataSet(tag);
DataSpace sid1 = dataset.getSpace();
hssize_t n = sid1.getSimpleExtentNpoints();
int ndims1 = sid1.getSimpleExtentNdims();
ndims1 = sid1.getSimpleExtentDims(tdims1);
datatype = dataset.getDataType();
dtype = datatype.getClass();
cout << ", StorageSize1=" << (size_t)dataset.getStorageSize();
cout << ", StorageSize2=" << (size_t)datatype.getSize();
switch(dtype)
{
case H5T_INTEGER:
a = new int[n];
dataset.read(a,datatype);
break;
case H5T_FLOAT:
b = new float[n];
dataset.read(b,datatype);
break;
case H5T_STRING:
dataset.read((void*)c, tid1);
break;
default:
cout <<", Type = something"<<endl;
break;
}
Question:
Since Character datasets are also stored as Equivalent ASCII int values, how would you differentiate between what exact type of the dataset, when dataset would return
datatype as H5T_INTEGER for both native_char and native_int datasets ? (one approach would be to get storage size and elements and analyse what exact datatype
to which data belongs to.)
Similarly, how would i know whether data is native_float or native_double ?
It would be great if somebody can tell me/provide some suggestion on this.
Thanks
Anish Anto
···
---------------------------------
Looking for last minute shopping deals? Find them fast with Yahoo! Search.
