Create MonteCarloDistribution.pde

introduction/MonteCarloDistribution/MonteCarloDistribution.pde

@@ -0,0 +1,57 @@
+// Daniel Shiffman
+// The Nature of Code
+// http://www.shiffman.net
+
+float[] vals;
+float[] norms;
+
+void setup () {
+  size (400, 300);
+
+  vals = new float[width];
+  norms = new float[width];
+}
+
+void draw () {
+  background(100);
+
+  float n = montecarlo();
+
+  int index = int (n * width);
+  vals[index]++;
+  stroke(255);
+
+  boolean normalization = false;
+  float maxy = 0.0;
+
+  for (int x = 0; x < vals.length; x++) {
+    line (x, height, x, height-norms[x]);
+    if (vals[x]>height) normalization = true;
+    if (vals[x]>maxy) maxy = vals[x];
+  }
+
+  for (int x = 0; x < vals.length; x++) {
+    if (normalization) norms[x] = (vals[x] / maxy) * (height);
+    else norms[x] = vals[x];
+  }
+}
+
+float montecarlo () {
+  boolean foundone = false;
+  int hack = 0;
+
+  while (!foundone && hack < 10000) {
+    float r1 = (float) random (1);
+    float r2 = (float) random (1);
+    float y = r1 * r1;
+
+    if (r2 < y) {
+      foundone = true;
+      return r1;
+    }
+
+    hack++;
+  }
+
+  return 0;
+}