// random() versus noise()
// Press r for seeing random() generated lines
// n for seeing noise() generated lines
void setup() {
  size(500, 500);
  smooth();
} // setup()

void draw() {
} // draw()

void keyPressed() {
  background(#407EFF);
  if (key == 'r') {
    // draw lines across the sketch with random heights
    stroke(#A50A0F);
    for (int i=0; i < width; i++) {
      line(i, height, i, height-random(height/2));
    }
  }
  else if (key == 'n') {
    float t = 0.0;
    stroke(#A50A0F);
    for (int i=0; i < width; i++) {
      line(i, height, i, height-noise(t)*height/2);
      t+= 0.01;
    }
  }
} // keyPressed()