int numFrames = 12;  // The number of frames in the animation
  int frame = 0;
  PImage[] images = new PImage[numFrames];
      
  void setup()
  {
    size(200, 200);
    frameRate(30);
    
    images[0]  = loadImage("PT_anim0000.gif");
    images[1]  = loadImage("PT_anim0001.gif"); 
    images[2]  = loadImage("PT_anim0002.gif");
    images[3]  = loadImage("PT_anim0003.gif"); 
    images[4]  = loadImage("PT_anim0004.gif");
    images[5]  = loadImage("PT_anim0005.gif"); 
    images[6]  = loadImage("PT_anim0006.gif");
    images[7]  = loadImage("PT_anim0007.gif"); 
    images[8]  = loadImage("PT_anim0008.gif");
    images[9]  = loadImage("PT_anim0009.gif"); 
    images[10] = loadImage("PT_anim0010.gif");
    images[11] = loadImage("PT_anim0011.gif"); 
    
    // If you don't want to load each image separately
    // and you know how many frames you have, you
    // can create the filenames as the program runs.
    // The nf() command does number formatting, which will
    // ensure that the number is (in this case) 4 digits.
    //for(int i=0; i<numFrames; i++) {
    //  String imageName = "PT_anim" + nf(i, 4) + ".gif";
    //  images[i] = loadImage(imageName);
    //}
  } 
   
  void draw() 
  { 
    frame = (frame+1)\%numFrames;  // Use % to cycle through frames
    image(images[frame], 0, 0);
  }