title: Tkinter coordinates start at 3?
body: <p>I have the following code:</p>
  
  <pre><code>from Tkinter import *
  
  master = Tk()
  canvas = Canvas(master, width=640, height=480, bd=0)
  canvas.pack()
  
  line_coords = (3, 3, 3, 100)
  canvas.create_line(*line_coords, fill='red')
  
  mainloop()
  </code></pre>
  
  <p>This will draw a line in the top-left corner. Why is it that if I change line_coords to (2, 2, 2, 100) the line does not render? It's as if the coordinate system starts at (3, 3).</p>