Change code to paralle computing (for loop -> parfor loop)

Question

Jae-Hee Park 2022-6-10

0
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https://ww2.mathworks.cn/matlabcentral/answers/1737635-change-code-to-paralle-computing-for-loop-parfor-loop

回答： Walter Roberson 2022-6-10

采纳的回答： Walter Roberson

在 MATLAB Online 中打开

Hi

I am trying to change a code that has double for loop to parfor loop(outside for becomes parfor).

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 = zeros(npulse,nrbin);
for k=1:npulse
    R_real = R_ori + R_ori .* (1-D_fa_rcmc(k,:)) ./ D_fa_rcmc(k,:);
    z = fft(ft_rcd(k,:));
    zp = [z(1:half_len) zeros(1, zpadlen) z(half_len+1:end)];
    tf_sub = ifft(zp) * m;
    tf_sub= [tf_sub tf_sub(1, end:-1:1)];
    idx = round((R_real-R_ori)/ori_sam_dist*m);
       
    for rn=1:nrbin
        ft_mcd(k,rn) = tf_sub(1, 1 + m*(rn-1) + idx(rn));
     end
end
%

parfor code

ft_mcd = zeros(npulse,nrbin);
parfor k = 1:npulse
    temp_k = k;
    temp_D_fa_rcmc = D_fa_rcmc;
    temp_ft_rcd = ft_rcd;
    R_real = R_ori + R_ori .* (1 - temp_D_fa_rcmc(temp_k,:)) ./ temp_D_fa_rcmc(temp_k,:);
    z = fft(temp_ft_rcd(temp_k,:));
    zp = [z(1:half_len) zeros(1, zpadlen) z(half_len + 1:end)];
    tf_sub = ifft(zp) * m;
    tf_sub2 = [tf_sub tf_sub(1, end:-1:1)];
    idx = round((R_real-R_ori)/ori_sam_dist*m);
    temp_ft_mcd = zeros(npulse,nrbin);
    for rn=1:nrbin
        temp_rn = rn;
        temp_index = 1 + m*(temp_rn-1) + idx(temp_rn);
        temp_ft_mcd(temp_k,temp_rn) = tf_sub2(1, temp_index);
    end
    ft_mcd(k,:) = temp_ft_mcd(k,:);
end