Python code coverage for Lib/turtledemo/planet_and_moon.py

#	count	content
1	n/a	#!/usr/bin/env python3
2	n/a	""" turtle-example-suite:
3	n/a
4	n/a	tdemo_planets_and_moon.py
5	n/a
6	n/a	Gravitational system simulation using the
7	n/a	approximation method from Feynman-lectures,
8	n/a	p.9-8, using turtlegraphics.
9	n/a
10	n/a	Example: heavy central body, light planet,
11	n/a	very light moon!
12	n/a	Planet has a circular orbit, moon a stable
13	n/a	orbit around the planet.
14	n/a
15	n/a	You can hold the movement temporarily by
16	n/a	pressing the left mouse button with the
17	n/a	mouse over the scrollbar of the canvas.
18	n/a
19	n/a	"""
20	n/a	from turtle import Shape, Turtle, mainloop, Vec2D as Vec
21	n/a
22	n/a	G = 8
23	n/a
24	n/a	class GravSys(object):
25	n/a	def __init__(self):
26	n/a	self.planets = []
27	n/a	self.t = 0
28	n/a	self.dt = 0.01
29	n/a	def init(self):
30	n/a	for p in self.planets:
31	n/a	p.init()
32	n/a	def start(self):
33	n/a	for i in range(10000):
34	n/a	self.t += self.dt
35	n/a	for p in self.planets:
36	n/a	p.step()
37	n/a
38	n/a	class Star(Turtle):
39	n/a	def __init__(self, m, x, v, gravSys, shape):
40	n/a	Turtle.__init__(self, shape=shape)
41	n/a	self.penup()
42	n/a	self.m = m
43	n/a	self.setpos(x)
44	n/a	self.v = v
45	n/a	gravSys.planets.append(self)
46	n/a	self.gravSys = gravSys
47	n/a	self.resizemode("user")
48	n/a	self.pendown()
49	n/a	def init(self):
50	n/a	dt = self.gravSys.dt
51	n/a	self.a = self.acc()
52	n/a	self.v = self.v + 0.5dtself.a
53	n/a	def acc(self):
54	n/a	a = Vec(0,0)
55	n/a	for planet in self.gravSys.planets:
56	n/a	if planet != self:
57	n/a	v = planet.pos()-self.pos()
58	n/a	a += (Gplanet.m/abs(v)3)v
59	n/a	return a
60	n/a	def step(self):
61	n/a	dt = self.gravSys.dt
62	n/a	self.setpos(self.pos() + dt*self.v)
63	n/a	if self.gravSys.planets.index(self) != 0:
64	n/a	self.setheading(self.towards(self.gravSys.planets[0]))
65	n/a	self.a = self.acc()
66	n/a	self.v = self.v + dt*self.a
67	n/a
68	n/a	## create compound yellow/blue turtleshape for planets
69	n/a
70	n/a	def main():
71	n/a	s = Turtle()
72	n/a	s.reset()
73	n/a	s.getscreen().tracer(0,0)
74	n/a	s.ht()
75	n/a	s.pu()
76	n/a	s.fd(6)
77	n/a	s.lt(90)
78	n/a	s.begin_poly()
79	n/a	s.circle(6, 180)
80	n/a	s.end_poly()
81	n/a	m1 = s.get_poly()
82	n/a	s.begin_poly()
83	n/a	s.circle(6,180)
84	n/a	s.end_poly()
85	n/a	m2 = s.get_poly()
86	n/a
87	n/a	planetshape = Shape("compound")
88	n/a	planetshape.addcomponent(m1,"orange")
89	n/a	planetshape.addcomponent(m2,"blue")
90	n/a	s.getscreen().register_shape("planet", planetshape)
91	n/a	s.getscreen().tracer(1,0)
92	n/a
93	n/a	## setup gravitational system
94	n/a	gs = GravSys()
95	n/a	sun = Star(1000000, Vec(0,0), Vec(0,-2.5), gs, "circle")
96	n/a	sun.color("yellow")
97	n/a	sun.shapesize(1.8)
98	n/a	sun.pu()
99	n/a	earth = Star(12500, Vec(210,0), Vec(0,195), gs, "planet")
100	n/a	earth.pencolor("green")
101	n/a	earth.shapesize(0.8)
102	n/a	moon = Star(1, Vec(220,0), Vec(0,295), gs, "planet")
103	n/a	moon.pencolor("blue")
104	n/a	moon.shapesize(0.5)
105	n/a	gs.init()
106	n/a	gs.start()
107	n/a	return "Done!"
108	n/a
109	n/a	if __name__ == '__main__':
110	n/a	main()
111	n/a	mainloop()