One would expect the following will fill up the plot window:

...

...

n=zeros(20000) n[::2]=1 plot(n)

The plot "stops" a little more than half way, as if it "runs out of ink". It happens on Linux as well as Solaris, using either numarray and Numeric, and both TkAgg and GTKAgg, but not GTK. Is this due to some AGG limitation? JC Hsu