Question

I would like to find out if there is a function that can generate random numbers from a set of numbers in Matlab? For instance say I have the set [-1 1]. How can I generate numbers from that set? I have tried to use randi([-1,1]) but that obviously will generate the numbers -1,0 and 1 and I would like to generate numbers uniformly WITHOUT the 0 and only include -1 and 1. I apologise in advance if this seems like a trivial question but I can’t seem to find the answer.

Thanks for any help you can provide.

Edit: I’ve found a simple solution for the above: (randi([0 1])*2) – 1. This only solves this problem and not a generation of numbers from a specified set.

Answer 1

Well, is there a function that can generate integers uniformly from the set 1:2, or, in general, from the set 1:n, where n is the number of elements in your set? (Yes)

If the above answer was yes, then can those numbers be used as an index into the generated set? (Yes)

A = [-1 1];
n = numel(A);
A(ceil(rand*n))

Will it sample randomly and uniformly? (Yes)