stroke(0, 0, 255);

  ly = map(0, f(4.7), f(3), height / 6, 9*height / 10);

  line(width / 10, ly, 9 * width / 10, ly);

  uy = map(0.1, f(4.7), f(3), height / 6, 9*height / 10);

  line(width / 10, ly, width / 10, height - uy);

​

  stroke(255, 0, 105);

  strokeWeight(5);

  for (let i = pA; i <= pB; i += sigma) {

    mx = map(i, 3, 6, width / 10, 9 * width / 10);

    my = map(f(i), f(3), f(4.7), height / 6, 9*height / 10);

    point(mx, my);

  }

}

​

function f(x) {

  return sin(x);

}

​

var pA = 3,

  pB = 6;

var epsilon = 0.5;

var sigma = 0.1;

​

function setup() {

  createCanvas(400, 400);

  background(31);

  fdraw();

}