shuffle matrix element in matlab
I have a martix and want to shuffle element of it .
x=[1 2 5 4 6 ]
after shuffle(something like this)
x=[2 4 6 5 1]
is matlab has function for it ? in php array_shuffle do this.
obtain shuffled indices using randperm
idx = randperm(length(x));
use indices to obtain shuffled vector
xperm = x(idx);
As an alternate to randperm, you can also use randsample from the statistics toolbox.
y = randsample(n,k) returns a k-by-1 vector y of values sampled uniformly at random, without replacement, from the integers 1 to n.
Note that it is "without replacement" (by default). So if you set k as length(x), it is equivalent to doing a random shuffle of the vector. For example:
x = 1:5; randsample(x,length(x)) %ans = % 4 5 3 1 2
I like this more than randperm, because it is easily extensible to different uses. For example, to draw 3 elements from x at random (like drawing from a bucket with finite items), you do randsample(x,3). Likewise, if you wish to draw 3 numbers, where the alphabet is made up of the elements of x, but allow for repetitions, you do randsample(x,3,true).