How can we create random numbers without using any function rand in matlab?

Question

b=round(rand(1,20));

Instead of using the function rand, I would like to know how to create such series.

https://en.m.wikipedia.org/wiki/Random_number_generation – Cris Luengo Apr 29 '18 at 01:13 — Cris Luengo, Apr 29 '18 at 01:13
Do you want to get zeros and ones as in your example? – Yuval Harpaz Apr 29 '18 at 14:33 — Yuval Harpaz, Apr 29 '18 at 14:33

Tommaso Belluzzo · Accepted Answer · 2018-04-29T14:47:47.200

This is a very interesting question. Actually, the easiest way to go, in my opinion is to use a Linear-feedback Shift Register. You can find plenty of examples and implementations googling around (here is one coming from another SO question).

Here is a quick Matlab demo based on this code:

b = lfsr(20)

function r = lfsr(size)
    persistent state;

    if (isempty(state))
        state = uint32(1);
    end

    if (nargin < 1)
        size = 1;
    end

    r = zeros(size,1);

    for i = 1:size
        r(i) = bitand(state,uint32(1));

        if (bitand(state,uint32(1)))
            state = bitxor(bitshift(state,-1),uint32(142));
        else
            state = bitshift(state,-1);
        end
    end
end

How can we create random numbers without using any function rand in matlab?

1 Answers1