matplotlib-users

[Matplotlib-users] problem with show()

[Daniel F. <da...@te...>]

Hi,

I'm learning how to use matplotlib and I'm having a problem with show().
I did the simplest example of the Tutorial on the Matplotlib's homepage:

from matplotlib.matlab import *
plot([1,2,3,4])
show()

It works fine, but when I try to run it again (second time on the same
session), the plot is not shown. I have another question too: when I run
the show() command, my program stops and only continues when I close the
plot windows. Is there anyway of show the plot and continues the program
with the plot window openned?

I'm using matplotlib 0.64.4-1 on a Debian GNU/Linux.


Sorry about my poor english.

Thanks.

Daniel.

[Matplotlib-users] problem with show()

[Chiara C. <chi...@es...>]

I,
I have a problem with showing plot. When I run this code:

figure(1)
semilogx(data[:,0],data[:,1])
savefig('try.png')
show()


It save the plot properly, but it doesn't show it. I tried to run it
with "--verbose-helpful" and this is the output:


matplotlib data path
/usr/local/lib/python2.4/site-packages/matplotlib/mpl-data
$HOME=/users/caronna
CONFIGDIR=/users/caronna/.matplotlib
loaded rc file
/usr/local/lib/python2.4/site-packages/matplotlib/mpl-data/matplotlibrc
matplotlib version 0.87.7
verbose.level helpful
interactive is False
platform is linux2
numerix numpy 1.0.1
font search path
['/usr/local/lib/python2.4/site-packages/matplotlib/mpl-data']
loaded ttfcache file /users/caronna/.matplotlib/ttffont.cache
backend Agg version v2.2

Does anyone know what's the problem?

Thanks,
Chiara

Re: [Matplotlib-users] problem with show()

[Russell E. O. <ro...@ce...>]

In article <45C...@es...>,
 Chiara Caronna <chi...@es...> wrote:

> I,
> I have a problem with showing plot. When I run this code:
> 
> figure(1)
> semilogx(data[:,0],data[:,1])
> savefig('try.png')
> show()
> 
> 
> It save the plot properly, but it doesn't show it. I tried to run it
> with "--verbose-helpful" and this is the output:
> 
> 
> matplotlib data path
> /usr/local/lib/python2.4/site-packages/matplotlib/mpl-data
> $HOME=/users/caronna
> CONFIGDIR=/users/caronna/.matplotlib
> loaded rc file
> /usr/local/lib/python2.4/site-packages/matplotlib/mpl-data/matplotlibrc
> matplotlib version 0.87.7
> verbose.level helpful
> interactive is False
> platform is linux2
> numerix numpy 1.0.1
> font search path
> ['/usr/local/lib/python2.4/site-packages/matplotlib/mpl-data']
> loaded ttfcache file /users/caronna/.matplotlib/ttffont.cache
> backend Agg version v2.2
> 
> Does anyone know what's the problem?

I'm not familiar with the "Agg" back end but I suspect it does not 
support output on a display. Try TkAgg, WXAgg or GTKAgg instead 
(depending what matplotlib was built to support) e.g. by editing 
~/.matplotlib/matplotlibrc

-- Russell

Re: [Matplotlib-users] problem with show()

[John H. <jdh...@ac...>]

>>>>> "Daniel" == Daniel Ferreira <da...@te...> writes:

    Daniel> Hi, I'm learning how to use matplotlib and I'm having a
    Daniel> problem with show().  I did the simplest example of the
    Daniel> Tutorial on the Matplotlib's homepage:

    Daniel> from matplotlib.matlab import * plot([1,2,3,4]) show()

    Daniel> It works fine, but when I try to run it again (second time
    Daniel> on the same session), the plot is not shown. I have
    Daniel> another question too: when I run the show() command, my
    Daniel> program stops and only continues when I close the plot
    Daniel> windows. Is there anyway of show the plot and continues
    Daniel> the program with the plot window openned?

    Daniel> I'm using matplotlib 0.64.4-1 on a Debian GNU/Linux.

Is this the right version number?  I didn't know matplotlib 0.64 was
out yet :-)

    Daniel> Sorry about my poor english.

I didn't even notice - it's not that poor!

The usage of show is a source of confusion to all new users of
matplotlib -- you are not alone.  Please see the FAQ
http://matplotlib.sf.net/faq.html#SHOW.  The main idea is that show is
only meant to be used in matplotlib scripts, not interactively from
the python shell.  If working interactively (type some commands, look
at a figure, type some more commands), you need to set interactive to
be True in your rc file.  Once you have done this (and restarted
python) you won't need to call show at all in an interactive session.
See also http://matplotlib.sf.net/interactive.html and
http://matplotlib.sf.net/.matplotlibrc.

I will try and update the tutorial to make this clearer.

For interactive work, I also recommend you set your backend to TkAgg
in your .matplotlibrc file.  Or use ipython with the pylab option -
google for matplotlib and ipython.

Hope this helps,
JDH