float x = 0; // change with horizontal position

void setup() {

  size(600, 400);
  noLoop();
}


void draw() {
  background(255);

  for (int i = 0; i < width; i++) {
    point(i, 150 + noise(x) * 200);
    x += 0.01;
  }
}

void keyPressed() {
  redraw();
}