circulo senoidal

float posY, diam, posX;
void setup(){
size(1080,720);
diam = 100;
posY = 0-diam;
posX = width/2;
}
void draw(){
  posY+=random(5);
  posX+=random(4);
  diam += 0.1;
//  background(0);
  ellipse(posX,posY,sin(diam)*100,sin(diam)*100);
  if (posY>height){
  posY=0;
  }
  if (posX>width){
   posX= 0;
  }
 
}