Lecture Notes on 14 Aug 2013

import math

class Point (object):
  # initializer
  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
  def __str__ (self):
    return '(' + str(self.x) + ', ' + str(self.y) + ')'

class Circle (object):
  # initializer
  def __init__ (self, x = 0, y = 0, radius = 1):
    self.center = Point (x, y)
    self.radius = radius

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

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

  # returns True if Circle c is strictly inside
  def is_inside (self, c):
    return (self.radius > ((self.center.dist (c.center)) + c.radius))

  # returns True if Circle c intersects 
  def does_intersect (self, c):
    return (self.center.dist (c.center) < (self.radius + c.radius))

  # string representation
  def __str__ (self):
    return 'Center = ' + str(self.center) + '  Radius = ' + str(self.radius)

class Rectangle (object):
  # initializer
  def __init__ (self, x1 = 0, y1 = 1, x2 = 1, y2 = 0):
    self.UL = Point (x1, y1)
    self.LR = Point (x2, y2)
 
  # compute area
  def area (self):
    return ((self.LR.x - self.UL.x) * (self.UL.y - self.LR.y))

  # compute perimeter
  def perimeter (self):
    return (2 * ((self.LR.x - self.UL.x) + (self.UL.y - self.LR.y)))

  # returns True of a point is strictly inside
  def is_inside (self, p):
    return ((p.x > self.UL.x) and (p.x < self.LR.x) and (p.y < self.UL.y)\
            and (p.y > self.LR.y))

  def is_inside (self, r):
    return self.is_inside (r.UL) and self.is_inside (r.LR)

def main():
  # Create Point objects
  p = Point (1, 2)
  print (p)
  q = Point (3, 4)
  print (q)
  p.x = 6
  p.y = 7
  print (p)
  print (p.dist(q))

  # Create Circle objects
  circleC = Circle (1, 1, 2)
  print (circleC)
  print (circleC.area())

main()