title: Finding the intersection of two circles
body: <p>I'm trying to find the intersections between two circles in Python(using Matplotlib) but can't get any values back.</p>
  
  <p>I'm doing this by creating lists of X's and Y's for each individual circle(Matplotlib takes the first argument as X values and the second one as  Y values when drawing a circle), and then intersecting the lists accordingly(e.g., circle1 x values with circle2 x values).</p>
  
  <pre><code>import numpy
  import math
  import matplotlib.pyplot as plt
  import random
  
  def origin_circle():
      global x_points
      global y_points
      global r
      global n
      r=1
      n=2**16
      x_points=[(r*math.cos(t)) for t in numpy.linspace(0, 2*numpy.pi*r, n+1)]
      y_points=[(r*math.sin(t)) for t in numpy.linspace(0, 2*numpy.pi*r, n+1)]
  
  def new_circle(x_offset, y_offset):
      global x_points1
      global y_points1
      x_points1=[x_offset+(r*math.cos(t)) for t in numpy.linspace(0, 2*numpy.pi*r, n+1)]
      y_points1=[y_offset+(r*math.sin(t)) for t in numpy.linspace(0, 2*numpy.pi*r, n+1)]
  
  origin_circle()
  new_center= random.randint(0, len(x_points))
  x_offset = x_points[new_center]
  y_offset = y_points[new_center]
  new_circle(x_offset, y_offset)
  print(set(x_points1).intersection(set(x_points)))
  print(set(y_points1).intersection(set(y_points)))
  </code></pre>
  
  <p>I expected to get values back, but the set that returned was empty.</p>