Hi Rafal,
(Sorry for misspelling your name earlier!)
Thank you for finding this error. I had that line in the code for appending
double data, but then when I was writing the code for appending byte arrays
it somehow got lost. Now it works perfectly fine!
All the best,
Johan
> Hi Johan,
>
> Everything in your code seems to be fine, but since your initial dataset
> X-dimension is "0" (no rows when creating dataset) you have to call:
>
> H5D.set_extent(datasetId, count);
>
> right after you defined a new space dimensions in "count".
>
> See also my minimal working example in C++ (but using C API):
>
> int rank = 2;
> int nCols = 30;
> int nRows = 5;
> hsize_t tdims[rank] = {0, nCols};
> hsize_t maxdims[rank] = {H5S_UNLIMITED, nCols};
> hid_t space_2d = H5Screate_simple (rank, tdims, maxdims);
> hid_t plist = H5Pcreate(H5P_DATASET_CREATE);
> H5Pset_layout(plist, H5D_CHUNKED);
> hsize_t chunk[rank] = {1, nCols};
> H5Pset_chunk(plist, rank, chunk);
>
> hid_t datasetId = H5Dcreate(file_id, "TestDataset",
> H5T_NATIVE_DOUBLE, space_2d, H5P_DEFAULT, plist, H5P_DEFAULT);
>
> hsize_t newdims[rank] = {nRows, nCols};
> H5Dset_extent(datasetId, newdims);
> hid_t newspace = H5Dget_space(datasetId);
> hsize_t offset[rank] = {0, 0};
> H5Sselect_hyperslab(newspace, H5S_SELECT_SET, offset, NULL,
> newdims, NULL);
>
> hid_t tmemspace = H5Screate_simple(rank, newdims, NULL);
> double data[nCols * nRows];
> double step = 1.1;
> for(int r = 0; r < nRows; r++)
> {
> for(int c = 0; c < nCols; c++)
> {
> data[c + r * nCols] = step;
> step += 1.1;
> }
> }
>
> uint8_t *data_bytes = reinterpret_cast<uint8_t*>(data);
>
> H5Dwrite (datasetId, H5T_NATIVE_DOUBLE, tmemspace, newspace,
> H5P_DEFAULT, data_bytes);
>
> H5Sclose(newspace);
> H5Sclose(tmemspace);
> H5Dclose(datasetId);
> H5Pclose(plist);
> H5Sclose(space_2d);
>
>
> Best regards,
> Rafal
>
>
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