并行化 MATLAB 代码

Question

您好，我想使用并行化我的 MATLAB 代码来运行高计算服务器。它是为深度学习制作图像数据库的代码。为了并行化我发现我必须 for parfor 循环的代码。但是我在第一个循环或第二个循环中使用了它，它显示错误 parfor 由于变量 imdb 和 image_counter 而无法运行。任何人都请帮我更改代码以使用 parfor

for i = 1:length(cur_images)
            X = sprintf('image Numb: %d ',i);
            disp(X)
        cur_image = load(cur_images{i,:});
        cur_image=(cur_image.Image.crop);


        %----------------------------------------------

        cur_image = imresize(cur_image, image_size);


        if(rgb < 1)
            imdb.images.data(:,:,1,image_counter) = cur_image;
        else
            imdb.images.data(:,:,1,image_counter) = cur_image(:,:,1); 
            imdb.images.data(:,:,2,image_counter) = cur_image(:,:,2);
            imdb.images.data(:,:,3,image_counter) = cur_image(:,:,3); 
            imdb.images.data(:,:,4,image_counter) = cur_image(:,:,4); 
            imdb.images.data(:,:,5,image_counter) = cur_image(:,:,5); 
            imdb.images.data(:,:,6,image_counter) = cur_image(:,:,6); 
            imdb.images.data(:,:,7,image_counter) = cur_image(:,:,7); 
            imdb.images.data(:,:,8,image_counter) = cur_image(:,:,8); 
            imdb.images.data(:,:,9,image_counter) = cur_image(:,:,9); 
            imdb.images.data(:,:,10,image_counter) = cur_image(:,:,10);

        end


        imdb.images.set(     1,image_counter) = set;             
        image_counter = image_counter + 1;
    end

Answer 1

这里的主要问题是您无法按照您尝试的方式分配给parfor 内的结构字段。此外，您的输出需要由循环变量索引以符合"sliced" - 即不要使用image_counter。综上所述，您需要更多类似的东西：

% Make a numeric array to store the output.
data_out = zeros([image_size, 10, length(cur_images)]);

parfor i = 1:length(cur_images)
    cur_image = load(cur_images{i, :});
    cur_image=(cur_image.Image.crop);
    cur_image = imresize(cur_image, image_size);

    % Now, assign into 'data_out'. A little care needed
    % here.
    if rgb < 1
        data_tmp = zeros([image_size, 10]);
        data_tmp(:, :, 1) = cur_image;
    else
        data_tmp = cur_image;
    end
    data_out(:, :, :, i) = data_tmp;
end
imdb.images.data = data_out;