change code to use GPU

Hi

I am trying to change a code that has double for loop to use GPU(single gpu right now).

But it seems fall in endless loop,because simple double for loop ends almost 300 sec but parfor and inner for loop does not end when elapsed 1000 sec over.

please find my error in my code below.

Thank you.

original code

ft_mcd = gpuArray(zeros(npulse,nrbin)); %19454x9098 array
parfor k = 1:npulse
    
    R_real = gpuArray(R_ori + R_ori .* (1 - D_fa_rcmc(k,:)) ./ D_fa_rcmc(k,:)); % 1x9098 array
    z = gpuArray(fft(temp_ft_rcd(k,:))); %1x9098 array
    zp = gpuArray([z(1:half_len) zeros(1, zpadlen) z(half_len + 1:end)]); %1x72784 array
    tf_sub = gpuArray(ifft(zp) * m); %1x72784 array
    tf_sub2 = gpuArray([tf_sub tf_sub(1, end:-1:1)]); %1x145568 array
    idx = gpuArray(round((R_real-R_ori)/ori_sam_dist*m)); %1x9098 array
    temp_ft_mcd = gpuArray(zeros(1,nrbin));%1x9098 array
    
    for rn=1:nrbin
        temp_index = gpuArray(1 + m*(rn-1) + idx(rn));%number
        temp_ft_mcd(1,rn) = tf_sub2(1, temp_index);%1x9098 array
    end
    
    ft_mcd(k,:) = temp_ft_mcd(k,:); %19454x9098 array
end

[Joss Knight]

I can't really tell what your question is, but your use of gpuArray is wrong. You don't wrap the result of an operation in gpuArray you move the input.

NO: z = gpuArray(fft(temp_ft_rcd(k,:)));

YES: temp_ft_rcd = gpuArray(temp_ft_rcd); z = fft(temp_ft_rcd(k,:));

Now z is a gpuArray so any operations on it will continue to take place on the GPU.