// Learning Processing
  // Daniel Shiffman
  // http://www.learningprocessing.com
  
  // Example 4-4: Many variables
  
  // We've got 8 variables now!  All  of type float.
  float circleX = 0;
  float circleY = 0;
  float circleW = 50;
  float circleH = 100;
  float circleStroke = 255;
  float circleFill = 0;
  float backgroundColor = 255;
  float change = 0.5;
  
  // Your basic setup
  void setup() {
    size(200,200);
    smooth();
  }
  
  void draw() {
    // Draw the background and the ellipse
    // Variables are used for everything: background, stroke, fill, location, and size.
    background(backgroundColor);
    stroke(circleStroke);
    fill(circleFill);
    ellipse(circleX,circleY,circleW,circleH);
  
    // Change the values of all variables
    // The variable change is used to increment and decrement the other variables.
    circleX = circleX + change;
    circleY = circleY + change;
    circleW = circleW + change;
    circleH = circleH - change;
    circleStroke = circleStroke - change;
    circleFill = circleFill + change;
  }