plot a square.

[Peter Brooker <ra5589(at)email.sps.mot.com>]

Assume that I have the following data
x=[0,1,1,0]
y=[0,0,1,1]

this defines a square.

plot,x,y

results in a "non-square" plot.

Is there an easy way to tell IDL to adjust the window size so that the
square will plot as a square on my screen?

thanks