Cookbook : Datasets

Reading a dataset of any type and dimensions

This snippet reads a dataset from the specified file.

    Private Function Read_dataset(ByVal hdf5file As Long, ByVal dsname As String)
        Dim dsID = H5D.open(hdf5file, dsname, H5P.DEFAULT)
        Dim spaceID = H5D.get_space(dsID)
        Dim typeID = H5D.get_type(dsID)
        Dim rank = H5S.get_simple_extent_ndims(spaceID)
        Dim dims(rank - 1) As ULong
        Dim maxDims(rank - 1) As ULong
        H5S.get_simple_extent_dims(spaceID, dims, maxDims)
        Dim sizeData = H5T.get_size(typeID)
        Dim size = sizeData.ToInt32()
        Dim bytearray_elements = 1
        For i = 0 To dims.Length - 1
            bytearray_elements *= dims(i)
        Next
        Dim dataBytes(bytearray_elements * CULng(size)) As Byte

        Dim pinnedArray As GCHandle = GCHandle.Alloc(dataBytes, GCHandleType.Pinned)

        H5D.read(dsID, typeID, H5S.ALL, H5S.ALL, H5P.DEFAULT, pinnedArray.AddrOfPinnedObject())
        pinnedArray.Free()
        For i = 0 to bytearray_elements - 1:
            Dim slice = dataBytes.Skip(i * size).Take(size).ToArray()
            Dim val = BitConverter.ToInt32(slice, 0) ' This line depends on the type of your dataset
        Next
       
    End Function