I have a 256 x 256 matrix which has value 1 inside a small square 20 x 20 around the center, and zero elsewhere. I need to randomly choose say 5% elsewhere to be 1 also. How do I go about this?
Thank you.
MATLAB: How to randomly choose 5% of a matrix to be of value 1.
matrix manipulation
Related Solutions
Try this:
% Make sample data.
x = linspace(0, 3*pi, 640);period = 2*pi;y = cos(2 * pi * x / period); % Noise-free signal.
% Noise is 5% of the signal value at each location,
% which means sigma is not a constant at each location.
amplitudes = y * 0.05;noise = amplitudes .* randn(1, length(y));% Add the noise to the noise-free signal.
yNoisy = y + noise;% Plot everything.
plot(x, yNoisy, 'r.', 'MarkerSize', 8);hold on;plot(x, y, 'b-', 'LineWidth', 2);grid on;
% Create matrix of 0s & 1s
M = round(rand(1024, 1280)); % List all indices of 1s
loc = find(M==1); % Randomly select one of the indices
randInd = datasample(loc, 1); % or randInd = loc(randi(numel(loc)))
% Show the row and col number of the selection
[row, col] = ind2sub(size(M), randInd);
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