def computeMotion(self):
"""Find the motion of a planet with its distance and its mass."""
angle = random.uniform(0, 2 * math.pi)
norm = self.distance
position = Vector.createFromPolarCoordonnates(norm, angle)
angle = (angle + math.pi / 2) % (2 * math.pi)
norm = self.speed # in m/s-1
velocity = Vector.createFromPolarCoordonnates(norm, angle)
acceleration = Vector.null()
return Motion(position, velocity, acceleration)
def showRadius(self,window,color=None,width=None):
"""Show the radius of the circle."""
if not color: color=self.radius_color
if not width: width=self.radius_width
vector=Vector.createFromPolarCoordonnates(self.radius,0,color=color)
vector.show(window,self.center,width=width)
vector.showText(surface,self.center,"radius",size=20)