save command in matlab parfor loop

Question

I'm trying to save a matrix within a parfor loop. I know matlab doesn't allow this and one needs to create a separate program. A bit of googling suggest creating a separate function, say parfor as follows:

  function parsave(fname, x,y)

    save(fname, 'x', 'y')

   end

The problem I'm encountering is that the program seems to be halting without any error before going through all of the iterations (i.e., it is saving about half of the files). I've got quite a lot of small files (around 1M). Could this be the problem?

Thanks in advance

user1375 user1375 · Accepted Answer · 2013-01-17T20:47:48

Calling save directly within parfor violates transparency requirements. Instead you need to pass your variables to another function within which you can call save.

An example Matlab provides is the following.

Save the following as "parsave.m":

    function parsave(fname, x,y)
    save(fname, 'x', 'y')
    end

Then run it with:

    parfor ii = 1:4
    x = rand(10,10);
    y = ones(1,3);
    parsave(sprintf('output%d.mat', ii), x, y);
    end

save command in matlab parfor loop

1 Answers