toggle navbar
How to Think like a Computer Scientist
Search
Table of Contents
Book Index
Scratch Activecode
Help
FAQ
Instructors Guide
About Runestone
Report A Problem
Astronomy Animation
¶
Object-oriented programming
¶
import turtle import math class SolarSystem: def __init__(self, width, height): self.thesun = None self.planets = [] self.ssturtle = turtle.Turtle() self.ssturtle.hideturtle() self.ssscreen = turtle.Screen() self.ssscreen.setworldcoordinates(-width/2.0,-height/2.0,width/2.0,height/2.0) # self.ssscreen.tracer(50) def addPlanet(self, aplanet): self.planets.append(aplanet) def addSun(self, asun): self.thesun = asun def showPlanets(self): for aplanet in self.planets: print(aplanet) def freeze(self): self.ssscreen.exitonclick() def movePlanets(self): G = .1 dt = .001 for p in self.planets: p.moveTo(p.getXPos() + dt * p.getXVel(), p.getYPos() + dt * p.getYVel()) rx = self.thesun.getXPos() - p.getXPos() ry = self.thesun.getYPos() - p.getYPos() r = math.sqrt(rx**2 + ry**2) accx = G * self.thesun.getMass()*rx/r**3 accy = G * self.thesun.getMass()*ry/r**3 p.setXVel(p.getXVel() + dt * accx) p.setYVel(p.getYVel() + dt * accy) class Sun: def __init__(self, iname, irad, im, itemp): self.name = iname self.radius = irad self.mass = im self.temp = itemp self.x = 0 self.y = 0 self.sturtle = turtle.Turtle() self.sturtle.shape("circle") self.sturtle.color("yellow") def getName(self): return self.name def getRadius(self): return self.radius def getMass(self): return self.mass def getTemperature(self): return self.temp def getVolume(self): v = 4.0/3 * math.pi * self.radius**3 return v def getSurfaceArea(self): sa = 4.0 * math.pi * self.radius**2 return sa def getDensity(self): d = self.mass / self.getVolume() return d def setName(self, newname): self.name = newname def __str__(self): return self.name def getXPos(self): return self.x def getYPos(self): return self.y class Planet: def __init__(self, iname, irad, im, idist, ivx, ivy, ic): self.name = iname self.radius = irad self.mass = im self.distance = idist self.x = idist self.y = 0 self.velx = ivx self.vely = ivy self.color = ic self.pturtle = turtle.Turtle() #self.pturtle.speed('fast') self.pturtle.up() self.pturtle.color(self.color) self.pturtle.shape("circle") self.pturtle.goto(self.x,self.y) self.pturtle.down() def getName(self): return self.name def getRadius(self): return self.radius def getMass(self): return self.mass def getDistance(self): return self.distance def getVolume(self): v = 4.0/3 * math.pi * self.radius**3 return v def getSurfaceArea(self): sa = 4.0 * math.pi * self.radius**2 return sa def getDensity(self): d = self.mass / self.getVolume() return d def setName(self, newname): self.name = newname def show(self): print(self.name) def __str__(self): return self.name def moveTo(self, newx, newy): self.x = newx self.y = newy self.pturtle.goto(newx, newy) def getXPos(self): return self.x def getYPos(self): return self.y def getXVel(self): return self.velx def getYVel(self): return self.vely def setXVel(self, newvx): self.velx = newvx def setYVel(self, newvy): self.vely = newvy def createSSandAnimate(): ss = SolarSystem(2,2) sun = Sun("SUN", 5000, 10, 5800) ss.addSun(sun) m = Planet("MERCURY", 19.5, 1000, .25, 0, 2, "blue") ss.addPlanet(m) m = Planet("EARTH", 47.5, 5000, 0.3, 0, 2.0, "green") ss.addPlanet(m) m = Planet("MARS", 50, 9000, 0.5, 0, 1.63, "red") ss.addPlanet(m) m = Planet("JUPITER", 100, 49000, 0.7, 0, 1, "black") ss.addPlanet(m) m = Planet("Pluto", 1, 500, 0.9, 0, .5, "orange") ss.addPlanet(m) m = Planet("Asteroid", 1, 500, 1.0, 0, .75, "cyan") ss.addPlanet(m) numTimePeriods = 10000 for amove in range(numTimePeriods): ss.movePlanets() ss.freeze() createSSandAnimate()
You have attempted
of
activities on this page