class Pulse {
  /* attributes */
  int SCALE = 10;
  int x;    // x-coordinate of the pulse
  int y;    // y-coordinate of the pulse
  float s;  // size of the pulse
  color c;  // color of the pulse
  
  /* methods */
  // constructor
  public Pulse(int pulseX, int pulseY, color pulseColor) {
    x = pulseX;
    y = pulseY;
    s = 0; 
    c = pulseColor;
  }
  
  // moves the pulse to the given position
  void move(int newX, int newY) {
    x = newX;
    y = newY;
  }
  
  // draws the pulse and updates its size
  void draw() {
    fill(c);
    ellipse(x, y, sin(s)*SCALE, sin(s)*SCALE);
    s += 0.1;
  }
}