matlabhdf5mat-file

How to specify the chunksize of large array saved in -v7.3 matfile?


I'm saving large data array to mat file.

m = matfile('data.mat','writable',true);
m.X(1000,1000,10,50000) = nan(1,'single');
for ii = 1 : 50000
  % do some computation
  m.X(1:1000,1:1000,1:10,ii) = Y;
end

How can I set ChunkSize of X to [1000,1000,1,1]?


Solution

  • You can't use the matfile command, but you use the HDF5 api. Since matfiles v7.3 use the HDF5 format, i guess it should also work on the reading side for you? Here is a small example from the documentation:

    h5create('myfile.h5','/DS3',[20 Inf],'ChunkSize',[5 5]);
    for j = 1:10
          data = j*ones(20,1);
          start = [1 j];
          count = [20 1];
          h5write('myfile.h5','/DS3',data,start,count);
    end
    h5disp('myfile.h5');
    

    Source of the example