How to use the Processing Library in the Trinket.io Web Based Coding Environment

peters_cool_processing_example.py

# NOTE: To run processing in the trinket.io environment,
# you need to import sin from math and import all from
# processing. Also, make sure to call run() at the very
# end of your python script!

# Code by Peter Farrell from his book 
# Math Adventures with Python
from math import sin
from processing import *

#CircleSineWave.pyde
r1 = 100 #radius of big circle
r2 = 10  #radius of small circle
t = 0 #time variable
circleList = []

def setup():
    size(600,600)
    
def draw():
    global t, circleList
    background(200)
    #move to left-center of screen
    translate(width/4,height/2)
    noFill() #don't color in the circle
    stroke(0) #black outline
    ellipse(0,0,2*r1,2*r1)
    
    #circling ellipse:
    fill(255,0,0) #red
    y = r1*sin(t)
    x = r1*cos(t)
    #add point to list:
    circleList.insert(0,y)
    ellipse(x,y,r2,r2)
    stroke(0,255,0) #green for the line
    line(x,y,200,y)
    fill(0,255,0) #green for the ellipse
    ellipse(200,y,10,10)
    
    if len(circleList)>300:
        circleList.remove(circleList[-1])

    
    #loop over circleList to leave a trail:
    for i,c in enumerate(circleList):
        #small circle for trail:
        ellipse(200+i,c,5,5)

    t += 0.05
   
# Remember to call run() at the very end of your script!   
run()