Scale

Paramenters for the scale() function are values specified as decimal percentages. For example, the method call scale(2.0) will increase the dimension of the shape by 200 percent. Objects always scale from the origin.

from p5 import *

a = 0.0
s = 0.0

def setup():
        size(640, 360)
        no_stroke()

def draw():
        background(102)

        global a
        global s

        a = a + 0.04
        s = cos(a)*2

        translate(width/2, height/2)
        scale(s)
        fill(51)
        rect((-25, -25), 50, 50)

        translate(75, 0)
        fill(255)
        scale(s)
        rect((-25, -25), 50, 50)

if __name__ == '__main__':
  run()