summing logicals i times where i is taken from a matrix of integers

I have a matrix of integers R

and some sort of critical value

crit = 0.395

depending on the value of any integer (i) in this matrix I want to generate a second random identically sized matrix of integers containing the sum of i components of the logical

crit >= rand

that is, if i = 0, it would return 0

if i = 1, crit >= rand, it would return either 0 or 1

if i = 2, it would sum crit >= rand + crit >= rand and would return either 0,1 or 2

Thus if R is

R = [1 2 1; 2 3 0; 0 1 0]

it might return

[1 1 0; 2 2 0; 0 0 0]

or

[0 2 1; 1 1 0; 0 1 0]

etc

In reality R is large so I have to avoid loops.

Any help appreciated!

Answer 1

[Andrei Bobrov]

EDIT

crit = 0.395;

z = max(R(:));
n0 = numel(R);
s = size(R);
Lo = crit >= rand([s,z]);
ii = reshape(1:n0,s);
out = arrayfun(@(jj)sum(Lo(jj+(0:R(jj)-1)*n0)),ii);

or just

out = arrayfun(@(ii)sum(rand(ii,1) <= crit),R)

[J T]

Thanks for the reply and answer but it doesn't seem to address the randomisation I require from the expression

crit >= rand

which would need to be generated i times and then summed with i being the value of the integer for that particular element of the matrix.

[Andrei Bobrov]

corrected code

Answer 2

[J T]

I think that's probably genius and I'll test it to make sure I get the right exponential recoveries in my Monte Carlo simulation

Many thanks!