ho to change cell array elemen value to Nan, when using gpuarray?

Hello Everyone,

Maybe somebody has a solution for this case? I have gpu cellarray with 1x499 and cells within 5x5. I would like to find zeros and change them to Nan. What I managed to do is here:

SQ=cellfun(@(x)(x==0,NaN,x), SQ,'UniformOutput',false);

[Mantas Vaitonis]

Did change code a bit:

    SQ(cellfun(@(x) x == 0, SQ{:, :}, 'UniformOutput', false)) = {NaN};

However, didi receive this error: Error using cellfun Input #2 expected to be a cell array, was gpuArray instead.

Answer 1

[Edric Ellis]

Instead of a 1x499 cell array of 5x5 gpuArray matrices, why not consider a 5x5x499 array. You can convert your existing cell array like this:

SQ_array = cat(3, SQ{:}); % concatenate in 3rd dimension, result is 5x5x499

Then, you can simply do:

SQ_array(SQ_array == 0) = NaN;

To do this using cellfun, the simplest way is to use standardizeMissing:

cellfun(@(x) standardizeMissing(x, 0), SQ, 'UniformOutput', false)

[Mantas Vaitonis]

Greate, thank You. Is there a way to make it back to a 1x499 cell array of 5x5 gpuArray matrices?

[Edric Ellis]

You can use mat2cell, like this:

mat2cell(SQ_array, 5, 5, ones(1, 499))

but really, I suspect you'd be much better off retaining the array form if you can. A 5x5 matrix is usually much too small for the GPU to offer much benefit - you need to keep your GPU busy by feeding it lots of data all at once in a single array-based operation. You've got a much better chance with a 5x5x499 array.

[Mantas Vaitonis]

Ok, thank You, will try with 3D.