How to assign probability to a matrix element?

Hi,

was wondering if somebody know to do the following:

I want to generate a matrix of zeros and ones with some probability of an element being zero or one. For instance:

Let A be a matrix, then

A(i,j) = 1 with probability p; A(i,j) = 0 with probability 1-p;

for some i,j and 0<p<1.

Is there a function on matlab which I can use to fo this?

Answer 1

[Sean de Wolski]

x = rand(m,n) > p

Just compare a random value to p.

[Roger Stafford]

Sean, I think you mean

 x = rand(m,n) <= p

Answer 2

[Roger Stafford]

It isn't clear whether the elements' probabilities are all to be equal to a single value, p, or each element A(i,j) is to have its own individual probability p(i,j). If you mean the latter, let P be a matrix the same size as A in which an element p(i,j) is the probability that A(i,j) is 1, and otherwise it is to be 0. Do this:

 A = rand(size(P))<=P;