var n = 50; //density relative to mouseY

var b =0;

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(0);

  noFill();

  translate(width / 2, height / 2);

    //center reference ellipse

  noStroke();

  d0 = map(mouseY, 0, height, 100, 500); //size relative to mouseY

    d=d0+d0/10* sin(frameCount /4.6)

  ellipse(0, 0, d );

  //repeating ellipse

  var n = floor(map(mouseX, 0, width, 25, 200)); //density relative to mouseX

  for (a = 0; a < 2 * PI; a = a + 2 * PI / n) {

    stroke(150);

    ellipse(d / 2 * cos(a), d / 2 * sin(a), d);

  }

}