Creating a mat file with binary mask

I want to create a 256*256 mask.mat file, where the middle 32 lines will be white (binary 1) and in there will be 30 lines of 1, randomly other than these 32 lines. I tried the below code: what should I add:

row = 256;
col = 256;

mask = zeros(row, col);
mask(:, 113:144) = 1;

figure, imshow(mask);
save("new-created-mask.mat", "mask");

Answer 1

[Voss]

row = 256;
col = 256;

mask = zeros(row, col);

% 32 vertical lines in the middle (or one vertical line 32 columns wide)
mask(:, 113:144) = 1;

% create 30 other vertical lines at random:
idx_avail = 1:col;          % column indexes available for the new random lines
idx_avail(113:144) = [];    % don't allow random lines in the middle

% 30 random numbers chosen from idx_avail without repeats:
% randperm(N_avail,30) returns 30 unique integers between 1 and N_avail, inclusive
% then idx_avail(randperm(__)) converts those to indexes of columns of mask
N_avail = numel(idx_avail);
random_idx = idx_avail(randperm(N_avail,30));

% put the lines in place:
mask(:,random_idx) = 1;

figure, imshow(mask);
save("new-created-mask.mat", "mask");

[Gulfam Saju]

Thanks

[Voss]

You're welcome!

[Gulfam Saju]

Hello! I want to create somthing just like the uploaded file. I want to create one like (data.train) of the sampling_pattern.mat file. Can you help?