Translate if statement in code to math

Hey,

I have this piece of code that I'm trying understand what is going on. I usually use R, but had to look at a piece of code from matlab.

So can anyone tell me what this if statement does in math??

prob = exp(-dE / kT);

if dE <= 0 I I rand() <= prob;

spin(row, col) = - spin(row, col);

Cheers, Emil

Answer 1

[OCDER]

prob = exp(-dE / kT);
%define probability as prob = e^(-dE/kT), where dE and kT are some value

if dE <= 0 || rand() <= prob     
%if dE <= 0, OR a uniformly distributed random number from 0 to 1 is <= prob

    spin(row, col) = - spin(row, col); 
    %negate the sign of the value stored at (row, col) position of a matrix called spin

end
%end of the if statement