To pick a number randomly

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PK
PK on 11 Sep 2012
Can some one help in picking a number from a matrix for example i have matrix of the form A=[1 2 3 4 5; 6 6 7 5 8 ; 12 4 5 6 9] and i require to pick only one element randomly from the matrix but should not be the same element every time.

Accepted Answer

Andrei Bobrov
Andrei Bobrov on 11 Sep 2012
Edited: Andrei Bobrov on 11 Sep 2012
try this is code
A=[1 2 3 4 5; 6 6 7 5 8 ; 12 4 5 6 9];
a = unique(A);
b = a(histc(A(:),a) < 2);
idx = randperm(numel(b));
out = b(idx(1));
  1 Comment
PK
PK on 11 Sep 2012
its working fine can u please elaborate the working of code

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More Answers (1)

Rene
Rene on 11 Sep 2012
Edited: Rene on 11 Sep 2012
The answer of andrei does not give a truly random number since he uses the unique command.
This will:
A=[1 2 3 4 5; 6 6 7 5 8 ; 12 4 5 6 9];
B = round((length(A(:))-1)*rand+1);
A(B)
ps. as far as rand returns a truly random number
  2 Comments
PK
PK on 12 Sep 2012
this works fine and any method to select the numbers accordingly from first row first element to third row fifth element one after the other continuously in the manner of 1 2 3 4 5 6 6 7 5 8 12 4 5 6 9
Andrei Bobrov
Andrei Bobrov on 12 Sep 2012
Edited: Andrei Bobrov on 12 Sep 2012
A2 = reshape(A',[],1);
out = A2(randperm(numel(A),1));

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