// Learning Processing
  // Daniel Shiffman
  // http://www.learningprocessing.com
  
  // Example 13-4: Perlin noise
  
  float time = 0.0;
  float increment = 0.01;
  
  void setup() {
    size(200,200);
    smooth(); 
  }
  
  void draw() {
    background(255);
    
     // Get a noise value at "time" and scale it according to the window's width.
    float n = noise(time)*width;
    
    // With each cycle, increment the " time "
    time += increment;
    
    // Draw the ellipse with size determined by Perlin noise
    fill(0);
    ellipse(width/2,height/2,n,n);
  }