>Psychtoolbox>PsychProbability

[Y,index] = Sample(X)

Returns a random sample from X.
If X is a vector, returns a scalar sample from X, so Y = X(index).
If X is an m-by-n matrix, m>1 && n>1, samples each column of X:
for j=1:n, Y(j)=X(index(j),j).

Also see RandSample, Shuffle, SORT, and Randi.