sin/cos optimizations, cleanup, and optimizations

src/main.rs

@@ -2,19 +2,19 @@ use physarum::model;
 
 fn main() {
     // # of iterations to go through
-    let n_iterations = 512;
+    let n_iterations = 2048;
 
     // Size of grid and pictures
     let (width, height) = (256, 256);
 
     // # of agents
-    let n_particles = 1 << 24;
+    let n_particles = 1 << 20;
     println!("n_particles: {}", n_particles);
 
     let diffusivity = 1;
 
     // `n_populations` is the # of types of agents
-    let n_populations = 2;
+    let n_populations = 1;
     // let n_populations = 1 + rng.gen_range(1..4); // make # of populations between 2 and 5