MATLAB: Error with arrayfun and GPU computing part 2.

arrayfungpuMATLABParallel Computing Toolbox

I am tring to compute simple example on GPU:
    function C=myf(A,B,N)
    for i=1:N
        C(:,:,i)=(A(:,:,i)*B)^10;
    end
    end
With CPU it works:
    M = 100;       
K = 100;       
N = 1000;       
A=rand(M,K,N);
B=rand(K,M);
C=myf(A,B,N);
With GPU:
if true
  Aongpu=gpuArray(A);
  Bongpu=gpuArray(B);
  C=arrayfun(@myf,Aongpu,Bongpu,N);
end
It doesn't:
Error using parallel.gpu.GPUArray/arrayfun Matrix dimensions must agree.
Why?? Thanks in advance

Best Answer

When working with gpuArray data, the function that you pass to the arrayfun will be called with scalar values. In other words, your myf needs to accept scalars and return scalars, like so:
M = 100;
K = 100;
N = 1000;
A=rand(M,K,N);
B=rand(K,M);
myf = @(a, b, n) a + b + n % or something more appropriate
arrayfun(myf, gpuArray(A), gpuArray(B), N);
Related Question