Thread: [Matplotlib-users] ylim() problem

I'm getting a "crash" when using ipython and pylab on WinXP.

The problem shows up when I have a subplot and try to use ylim to
change the axis scale.  Here's an example (after plotting some data).

In [2]: ylim()
Out[2]: (0.0, 30000000000.0)

In [3]: xlim(-6, 6)
Out[3]: (-6, 6)

(axis scsale changes as expected)

In [4]: ylim(0, 1000)

( crash - i.e., CPU use goes to 100%, prompt does not return, Tkinter
and ipython windows unresponsive)

I just upgraded to pylab 0.81 (python 2.3.3) and see the same problem.
 I'm not sure how to debug this from python since I don't have a
prompt.  I did add some print statements to my original script and it
seems all commands execute in non-interactive mode until p.show().  If
I comment out the ylim() command the script works as expected.

-- David

>>>>> "Dave" == Dave  <da...@gm...> writes:

    Dave> I'm getting a "crash" when using ipython and pylab on WinXP.
    Dave> The problem shows up when I have a subplot and try to use
    Dave> ylim to change the axis scale.  Here's an example (after
    Dave> plotting some data).

    Dave> In [2]: ylim() Out[2]: (0.0, 30000000000.0)

    Dave> In [3]: xlim(-6, 6) Out[3]: (-6, 6)

    Dave> (axis scsale changes as expected)

    Dave> In [4]: ylim(0, 1000)

    Dave> ( crash - i.e., CPU use goes to 100%, prompt does not
    Dave> return, Tkinter and ipython windows unresponsive)


My guess is that you have data at 30000000000.0 and when you zoom in
to 1000 the data is so far out of the view lim that it is overflowing
an integer in the extension code.  This is a know bug, but if you post
a complete example on the sf site in the bug report section that
exposes us, it will help us fix it sooner rather than later.

Thanks,
JDH

On 6/13/05, John Hunter <jdh...@ac...> wrote:
> >>>>> "Dave" =3D=3D Dave  <da...@gm...> writes:
>=20
>    Dave> I'm getting a "crash" when using ipython and pylab on WinXP.
>    Dave> The problem shows up when I have a subplot and try to use
>    Dave> ylim to change the axis scale.  Here's an example (after
>    Dave> plotting some data).
>=20
>    Dave> In [2]: ylim() Out[2]: (0.0, 30000000000.0)
>=20
>    Dave> In [3]: xlim(-6, 6) Out[3]: (-6, 6)
>=20
>    Dave> (axis scsale changes as expected)
>=20
>    Dave> In [4]: ylim(0, 1000)
>=20
>    Dave> ( crash - i.e., CPU use goes to 100%, prompt does not
>    Dave> return, Tkinter and ipython windows unresponsive)
>=20
>=20
> My guess is that you have data at 30000000000.0 and when you zoom in
> to 1000 the data is so far out of the view lim that it is overflowing
> an integer in the extension code.  This is a know bug, but if you post
> a complete example on the sf site in the bug report section that
> exposes us, it will help us fix it sooner rather than later.
>=20
> Thanks,
> JDH
>=20


I'll see if I can reproduce it wirth a nice simple example suitable
for debug.  If so I'll post to sf.  Thanks.

By the way, the new autoscale flag will be used and appreciated here
just as soon as I can add it to my scripts.

- David