Clock Hands [codeskulptor]

import simplegui
import random
import math
#http://www.codeskulptor.org/#user43_xK6bwFYD2Mgvyy4_0.py

# math helper function
def dot(v, w):
    return v[0] * w[0] + v[1] * w[1]


WIDTH = 500
HEIGHT = 500

#The two vectors that are being added
vector1 = [0,100]
vector2 = [100,0]


#vector is drawn from the center of the canvas.
class vector:
    def __init__ (self, xy, color, rot):
        self.xy = xy
        self.color = color
        self.border = 2
        #initial x/y coords converted to polar coords (length, theta)
        self.length = math.sqrt(self.xy[0]*self.xy[0] + self.xy[1]*self.xy[1])
        self.theta = math.atan2(self.xy[1], self.xy[0])
        self.rot = rot

    def __str__ (self):
        print "Vector with coordinates "
        print self.xy
        print "Color is " + self.color
        return ""

    def update(self):
        #polar coords updtated by adding 3.14/rot to theta, then x/y coords updated
        self.theta += math.pi/self.rot
        self.xy[0] = self.length * math.cos(self.theta)
        self.xy[1] = self.length * math.sin(self.theta)



    def draw(self, canvas):
        canvas.draw_line((WIDTH/2,HEIGHT/2),
                         (WIDTH/2 + self.xy[0], HEIGHT/2 + self.xy[1]),
                         self.border, self.color)

class resultant:
    def __init__(self, vectorA, vectorB, color):
        self.coords = [vectorA.xy[0] + vectorB.xy[0], vectorA.xy[1] + vectorB.xy[1]]
        self.color = color
        self.border = 2

    def __str__ (self):
        print "Vector with coordinates "
        print self.coords
        print "Color is " + self.color
        return ""

    def update(self, vectorA, vectorB):
        #update function has to be passed both of the vectors to get most recent values for x/y
        self.coords = [vectorA.xy[0] + vectorB.xy[0], vectorA.xy[1] + vectorB.xy[1]]

    def draw(self,canvas):
        canvas.draw_line((WIDTH/2,HEIGHT/2),
                         (WIDTH/2 + self.coords[0], HEIGHT/2 + self.coords[1]),
                         self.border, self.color)

def draw(canvas):
    v1.update()
    v2.update()
    v3.update(v1, v2)
    v1.draw(canvas)
    v2.draw(canvas)
    v3.draw(canvas)



v1 = vector(vector1, "Red", 60)
v2 = vector(vector2, "White", -600)
v3 = resultant(v1, v2, "Green")


frame = simplegui.create_frame("Dot Product", WIDTH, HEIGHT)

frame.set_draw_handler(draw)

frame.start()