地球公转走向图:
from turtle import Shape, Turtle, mainloop, Vec2D as Vec
class GravSys(object):
def __init__(self):
self.planets = []
self.t = 0
self.dt = 0.01
def init(self):
for p in self.planets:
p.init()
def start(self):
for i in range(10000):
self.t += self.dt
for p in self.planets:
p.step()
class Star(Turtle):
def __init__(self, m, x, v, gravSys, shape):
Turtle.__init__(self, shape=shape)
self.penup()
self.m = m
self.setpos(x)
self.v = v
gravSys.planets.append(self)
self.gravSys = gravSys
self.resizemode("user")
self.pendown()
def init(self)