let distribution = Array(bins).fill(0);

  for(let s = 0; s < samples; ++s) {

    let x = 1, y = 1;

    while(x*x + y*y > 1) {

      x = random();

      y = random();

    }

    let i = floor(x*bins);

    distribution[i] += 1;

  }

  return distribution.map(p=>p/samples);

}

​

function setup() {

  createCanvas(400, 400);

  background(220);

  noLoop();

  let bins = 100;

  let samples = 1000000;

  let dist = createDistribution(bins, samples);

  for(let i = 0; i < bins; i++) {

    let px = i * width / bins;

    let y = dist[i];

    let py = height - y * height * bins * PI/4;

    point(px, py);

  }

/*  

  for(let i = 0; i < 100; i++) {

    let x = i / 100;

    let y = sqrt(1-x*x);

    let px = i * 4;

    let py = height * (1-y);

    point(px, py);

  }

*/  

}

​

​