Guide:TAUChapel

Chapel

MonteCarlo example

To test out some Chapel's language features let program a MonteCarlo simulation to calculate PI. We can calculate PI by assess how many points with coordinates x,y fit in the unit circle, ie x^2+y^2<=1.

Basic

Here is the basic routine that computes PI:

proc compute_pi(p_x: [] real(64), p_y: [] real(64)) : real {

 var c : sync int;
 c = 0;
 forall i in 1..n {
   if radius(p_x[i], p_y[i]) then
       c += 1;
 }
 return c * 4.0 / n;

}

Notice that the forall here will compute each iteration in parallel, hence the need to define variable c as a sync variable.