[Matplotlib-users] Vertical lines

[Nils W. <nw...@me...>]

Hi all,

How can I add vertical/horizontal  lines (x=constant, y=constant 
respectively) to an existing plot with matplotlib ?
A small example would be appreciated.

Is there a simple command to plot closed polygons, which are defined by 
the coordinates  of the vertices ?
 
Thanks in advance.

Nils