Randomly select one value from an Array.

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I have a 200x1 Cell Array, A, and I need to randomly select x values from that cell array. I tried using randperm in a loop but it seems to select the values in order from Array A. Also repetition is permitted.
for i=1:30
new_A=A(randperm(i))
end
  1 Comment
Stephen23
Stephen23 on 25 Jan 2023
"I tried using randperm in a loop but it seems to select the values in order from Array A."
That is how you wrote your code. The correct way to use RANDPERM() would be without a loop:
newA = A(randperm(200,30))

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Answers (2)

the cyclist
the cyclist on 24 Jan 2023
Here is one way to pull 30 random values (with possible repeats) from A.
randomIndex = randi(200,30,1);
new_A = A(randomIndex)

Image Analyst
Image Analyst on 24 Jan 2023
No loop needed. Try this to get x cells randomly chosen from a cell array, A, of any dimensions
randomIndexes = randi(numel(A), x, 1); % Linear indexes
output = A(randomIndexes); % Extract the cells into a new cell array.
Because we're using randi() instead of randperm(), it's possible to have some cells repeated in the output.

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