Lecture Notes on 22 Jan 2014

import math

class Point (object):
  # constructor
  def __init__ (self, x = 0, y= 0):
    self.x = x
    self.y = y

  # get distance
  def dist (self, p):
    return math.hypot (self.x - p.x, self.y - p.y)

  # string representation of a Point object
  def __str__ (self):
    return '(' + str(self.x) + ', ' + str(self.y) + ')'

class Circle (object):
  # constructor
  def __init__ (self, radius = 0, x = 0, y = 0):
    self.radius = radius
    self.center = Point (x, y)

  # compute circumference
  def circumference (self):
    return 2.0 * math.pi * self.radius

  # compute area
  def area (self):
    return math.pi * self.radius * self.radius

  # determine if point is inside circle
  def isInside (self, p):
    return (self.center.dist(p) < self.radius)

  # determine if a circle c is inside this circle
  def isWithin (self, c):
    distance = self.center.dist (c.center)
    return (distance + c.radius) < self.radius
 

def main ():
  # Create a Point object
  pointP = Point ()
  pointQ = Point (2.3, 4.5)

  # Print coordinates of the points
  print (pointP.x, pointP.y)
  print (pointQ.x, pointQ.y)

  # Change the coordinates
  pointP.x = 4.7
  pointP.y = 7.2
  print (pointP.x, pointP.y)
  print (pointP)

  # Print distance between points
  print (pointP.dist(pointQ))
  print (pointQ.dist(pointP))


main()