To pick a number randomly

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.

Answer 1

[Andrei Bobrov]

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));

[PK]

its working fine can u please elaborate the working of code

Answer 2

[Rene]

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

[PK]

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]

A2 = reshape(A',[],1);
out = A2(randperm(numel(A),1));