bug#346: plot not cleared after plot() commands following a plotyy()

[David Bateman <adb014@gmail.com>]

Thomas Weber wrote:
> thanks
> [let's give the tracker a try]
> 
> [ Octave 3.0.1, gnuplot 4.2 patchlevel 2 ]
> 
> The following code leaves fragments of the plotyy() commands in the
> final plot after the plot() command:
> 
> ===================================================================
> x= 1:10;
> y = 1./x;
> z = 10 *x;
> q = 100*x;
> 
> plotyy(x,y,x,z)
> pause
> plotyy(x,y,x,q)
> pause
> plot(x,y)
> ===================================================================


Not sure how to address this in the bug tracker as it should be marked
as "pending" for 3.1.x and "won't fix" for 3.0.x.. In any case its a
known problem. The thread

http://www.nabble.com/RE%3A--Changeset--plotyy-leaves-traces-of-previous-plots-tt16361090.html

discusses it and I even proposed a patch, that partially addresses the
issue, though potentially causes other problems and so John didn't want
to apply it. The solution that is proposed for 3.1.x is to use the
callback code in the octave-graphics branch to create a callback
function that deals with clearing the plotyy plots in the same manner as
 matlab does. However, we need the new graphics handle code in the main
tree, at least before I'd look at the problem. In any case its one of
the issues I have on my todo list.

D.