Circle is generated of random dots

dot_circle.pde

PVector location;
PVector velocity;
float rad;
int h = 0;

void setup() {
  size(900,900);
  
  //HSB color mode is a simple way to go through the entire
  //color scheme just by changing one variable.
  colorMode(HSB, 360, 100, 100);
  
  background(0,0,12);
  smooth();
}

void draw() {
  // looped circular movement
  println(frameCount);
  rad = radians(frameCount);
  
  // size of the circle, >350 – bigger, <350 – smaller.
  float x = width/2 + (350* cos(rad));
  float y = height/2 + (350 * sin(rad));

  location = new PVector(x, y);
  
  // velocity also determines the width of the ring.
  velocity = new PVector(random(-50, 200), random(-50, 20));
  location.add (velocity);
  
  stroke(h, 90, 90);
  fill(h, 90, 90);
  // size of the balls.
  ellipse(location.x, location.y, 10, 10);
  
  // when x reaches it max (completeting a full circle)
  // the color changes.
  if (x > 799.94) {
    h = h + 10;
  }
  // color reset
  if ( h > 360) {
    h = 0;
  }
}