matplotlib-users

[Matplotlib-users] pylab vs. embedding in wx

[Ryan K. <rya...@gm...>]

I have a problem that probably highlights a problem with how I
normally use mpl vs. how I should use it.  I have some utility scripts
that do various data processing tasks and also have convenience
functions for plotting data using pylab.  Almost all of my scripts
have a line like this near the top:
from pylab import figure, cla, clf, plot, subplot, show, ylabel,
xlabel, xlim, ylim, semilogx, legend, title, savefig

I am now trying to import some of my data processing functions into a
script that is embedding matplotib in a wxPython application following
the embedding_in_wx#.py examples.  I am getting this error:

ryan@am2:~/siue/Research/PythonSimulationEnvironment$ python SystemID_gui.py
Traceback (most recent call last):
  File "SystemID_gui.py", line 18, in ?
    import rwkbode
  File "/home/ryan/pythonutil/rwkbode/__init__.py", line 3, in ?
    import pylab
  File "/usr/lib/python2.4/site-packages/pylab.py", line 1, in ?
    from matplotlib.pylab import *
  File "/usr/lib/python2.4/site-packages/matplotlib/pylab.py", line 216, in ?
    from backends import new_figure_manager, draw_if_interactive, show
ImportError: cannot import name new_figure_manager

which seems to say that pylab cannot be imported after my wx mpl panel
has done this:
import matplotlib
import wx
from scipy import sin, cos, pi, atleast_1d, shape, log10
#from wxPython.wx import *
matplotlib.use('WXAgg')
import matplotlib.cm as cm
from matplotlib.backends.backend_wxagg import Toolbar, FigureCanvasWxAgg
from matplotlib.figure import Figure
import matplotlib.numerix as numerix
import matplotlib.numerix.mlab as mlab
from matplotlib.mlab import meshgrid


How should I be using matplotlib/pylab in my utility scripts so that
they are compatible with embedding in wx?

Thanks,

Ryan

Re: [Matplotlib-users] pylab vs. embedding in wx

[John H. <jd...@gm...>]

On 3/15/07, Ryan Krauss <rya...@gm...> wrote:

> How should I be using matplotlib/pylab in my utility scripts so that
> they are compatible with embedding in wx?

A good rule of thumb is to never import pylab at the top level for
modules that need to be imported.  In my own code, I often do
something like

  def somefunc(figfunc):
      fig = figfunc()
      ax = fig.add_subplot(111)
      ax.plot([1,2,3])

and then I can call it with

  somefunc(pylab.figure)

or a custom func that generates a GUI embedded figure instance.  Eg,
in my GTKApps, I have a functor like gtk_figure that returns a
function that creates a figure embedded in a GTK window.

In basemap, Jeffrey Whitaker does something like the following

  def somefunc(ax=None):
      if ax is None:
          import pylab
          ax = pylab.gca()

Here the pylab import is triggered only when the function is called
with default arguments.  That way you can use it from GUI code without
triggering a pylab import like

  somefunc(ax)

and from other code where you want pylab do do everything with

  somefunc()

I'm afraid you have some cleanup to do.....  Mixing pylab with
embedded GUI code is a recipe for pain and misery.

JDH

Re: [Matplotlib-users] pylab vs. embedding in wx

[Ryan K. <rya...@gm...>]

Thanks John.  I know I have some clean up to do, I just want to do it
right so it isn't an annual (or more often) thing....

On 3/15/07, John Hunter <jd...@gm...> wrote:
> On 3/15/07, Ryan Krauss <rya...@gm...> wrote:
>
> > How should I be using matplotlib/pylab in my utility scripts so that
> > they are compatible with embedding in wx?
>
> A good rule of thumb is to never import pylab at the top level for
> modules that need to be imported.  In my own code, I often do
> something like
>
>   def somefunc(figfunc):
>       fig = figfunc()
>       ax = fig.add_subplot(111)
>       ax.plot([1,2,3])
>
> and then I can call it with
>
>   somefunc(pylab.figure)
>
> or a custom func that generates a GUI embedded figure instance.  Eg,
> in my GTKApps, I have a functor like gtk_figure that returns a
> function that creates a figure embedded in a GTK window.
>
> In basemap, Jeffrey Whitaker does something like the following
>
>   def somefunc(ax=None):
>       if ax is None:
>           import pylab
>           ax = pylab.gca()
>
> Here the pylab import is triggered only when the function is called
> with default arguments.  That way you can use it from GUI code without
> triggering a pylab import like
>
>   somefunc(ax)
>
> and from other code where you want pylab do do everything with
>
>   somefunc()
>
> I'm afraid you have some cleanup to do.....  Mixing pylab with
> embedded GUI code is a recipe for pain and misery.
>
> JDH
>

Re: [Matplotlib-users] pylab vs. embedding in wx

[Ryan K. <rya...@gm...>]

I am learning the hard way that I don't know as much about matplotlib
as I thought I did except for how to use pylab.

I think I have managed to create a figure, add an axis, and plot
something on it without pylab, but I don't know how to do the
equivalent of show().  draw() needs a renderder and I can't seem to
figure out how to create one.  Here is what I have done so far:

myfig = pylab.Figure()
myaxes=myfig.add_axes((0,1,0,1))
t=arange(0,1,0.01)
y=sin(2*pi*t)
myaxes.plot(t,y)

What do I need to do to show the plot from the command line in IPython
(i.e. if I actually want to use pylab instead of OO)?

I may be going about this the wrong way and it may be easier just to
set up some imports of pylab that only trigger inside of functions,
but I would like to have functions that are useful either from the
IPython command line or in OOP situations.   Following the examples
for WX, I am doing this at the top of my OOP modules:

from matplotlib.backends.backend_wxagg import Toolbar, FigureCanvasWxAgg
from matplotlib.figure import Figure
.
.
.
	
class mplpanel(wx.Panel):
    def __init__(self, parent):
        wx.Panel.__init__(self, parent, -1)

        self.fig = Figure((5,5), 75)
        self.canvas = FigureCanvasWxAgg(self, -1, self.fig)


And the my drawing commands operate on self.fig and then the last line
of all plotting functions is self.canvas.draw().

So, it would be nice if my utility functions took a figure instance as
an input and operated on it.

Am I making any sense?  Am I going about this revision in a good way?

Thanks,

Ryan

On 3/15/07, Ryan Krauss <rya...@gm...> wrote:
> Thanks John.  I know I have some clean up to do, I just want to do it
> right so it isn't an annual (or more often) thing....
>
> On 3/15/07, John Hunter <jd...@gm...> wrote:
> > On 3/15/07, Ryan Krauss <rya...@gm...> wrote:
> >
> > > How should I be using matplotlib/pylab in my utility scripts so that
> > > they are compatible with embedding in wx?
> >
> > A good rule of thumb is to never import pylab at the top level for
> > modules that need to be imported.  In my own code, I often do
> > something like
> >
> >   def somefunc(figfunc):
> >       fig = figfunc()
> >       ax = fig.add_subplot(111)
> >       ax.plot([1,2,3])
> >
> > and then I can call it with
> >
> >   somefunc(pylab.figure)
> >
> > or a custom func that generates a GUI embedded figure instance.  Eg,
> > in my GTKApps, I have a functor like gtk_figure that returns a
> > function that creates a figure embedded in a GTK window.
> >
> > In basemap, Jeffrey Whitaker does something like the following
> >
> >   def somefunc(ax=None):
> >       if ax is None:
> >           import pylab
> >           ax = pylab.gca()
> >
> > Here the pylab import is triggered only when the function is called
> > with default arguments.  That way you can use it from GUI code without
> > triggering a pylab import like
> >
> >   somefunc(ax)
> >
> > and from other code where you want pylab do do everything with
> >
> >   somefunc()
> >
> > I'm afraid you have some cleanup to do.....  Mixing pylab with
> > embedded GUI code is a recipe for pain and misery.
> >
> > JDH
> >
>

Re: [Matplotlib-users] pylab vs. embedding in wx

[Ken M. <mc...@ii...>]

Ryan,

In my (limited) experience, it's dicey to mix pylab's plotting  
functionality and the OO API.  I guess I'm a little unclear exactly  
what your use case is for this.  It sounds like you're goal is to  
create a library of functions that operate on Figure instances,  
perhaps so you can use them both interactively and as part of a  
wxPython application.

If that's the case, I'd recommend you try using pylab's gcf() and draw 
() to acquire and redraw the current Figure instance from within  
IPython.  You can also save the return value of pylab's figure(),  
which returns a Figure that's already been attached to the  
appropriate renderer.  This way you can use the OO API for plotting  
without having to futz with the drawing machinery directly.

This script might give you some ideas about how to structure your  
code.  It contains several of the MPL examples re-coded as functions  
that accept a Figure instance and use the OO API for plotting.

	http://svn.csrri.iit.edu/mr-software/wxmpl/trunk/demos/plotting.py

Ken

Re: [Matplotlib-users] pylab vs. embedding in wx

[Ryan K. <rya...@gm...>]

Sorry, I just googled wxmpl and found your page and am now downloading
it.  I may have a more intelligent question momentarily.  You may
ignore that part of my response.

Ryan

On 3/19/07, Ryan Krauss <rya...@gm...> wrote:
> Thanks for your thoughts Ken.  Sorry, I assumed a bit on the context
> of my comments.  I have some data processing utility scripts and I
> want to now use with a WX application.  The problem is that the
> utility modules were written without any thought of this future use in
> mind and in all of them I have something like
>
> from pylab import figure, cla, clf, plot, semiliogx, show, ...
>
> at the top.  This makes them completely incompatible with embedding in
> a WX application.  So, I need to re-write them and I want to know how
> to do that best.  John had some suggestions and I had some new
> questions as I tried to act on his thoughts.  So, the actual plotting
> functions don't have to be re-useable in both contexts, but it would
> be nice.
>
> I can't actually run your code because I don't have the wxmpl.py
> module.  Looking at it, it looks like a really nice set of functions
> that work cleanly with embedding in a backend.  How could I call one
> of the functions from the command line?  Could I do something like:
> import plotting, pylab
> myfig = pylab.figure()
> plotting.plot_simple(myfig)
>
> and would I need any additional commands to actually show the figure?
>
> Let me know if that makes sense and please send me the wxmpl.py file
> or let me know where I can get it.
>
> Thanks again,
>
> Ryan
>
> On 3/19/07, Ken McIvor <mc...@ii...> wrote:
> > Ryan,
> >
> > In my (limited) experience, it's dicey to mix pylab's plotting
> > functionality and the OO API.  I guess I'm a little unclear exactly
> > what your use case is for this.  It sounds like you're goal is to
> > create a library of functions that operate on Figure instances,
> > perhaps so you can use them both interactively and as part of a
> > wxPython application.
> >
> > If that's the case, I'd recommend you try using pylab's gcf() and draw
> > () to acquire and redraw the current Figure instance from within
> > IPython.  You can also save the return value of pylab's figure(),
> > which returns a Figure that's already been attached to the
> > appropriate renderer.  This way you can use the OO API for plotting
> > without having to futz with the drawing machinery directly.
> >
> > This script might give you some ideas about how to structure your
> > code.  It contains several of the MPL examples re-coded as functions
> > that accept a Figure instance and use the OO API for plotting.
> >
> >         http://svn.csrri.iit.edu/mr-software/wxmpl/trunk/demos/plotting.py
> >
> > Ken
> >
>

Re: [Matplotlib-users] pylab vs. embedding in wx

[Ryan K. <rya...@gm...>]

Thanks to Ken and John, I think I am off and running.  Nice work on
wxmpl Ken!  I think it fills a significant need.

The two attached files show a ridiculously simple example of what I am
planning to do.  It may be completely obvoius to others.  test_plot.py
is an example of a module that can be used from the command line with
pylab and IPython and it can also be imported into a WX app (as
demonstrated by wx_compatible.py).  So, I will edit my data processing
scripts to use this approach.

Thanks again,

Ryan

On 3/19/07, Ryan Krauss <rya...@gm...> wrote:
> Sorry, I just googled wxmpl and found your page and am now downloading
> it.  I may have a more intelligent question momentarily.  You may
> ignore that part of my response.
>
> Ryan
>
> On 3/19/07, Ryan Krauss <rya...@gm...> wrote:
> > Thanks for your thoughts Ken.  Sorry, I assumed a bit on the context
> > of my comments.  I have some data processing utility scripts and I
> > want to now use with a WX application.  The problem is that the
> > utility modules were written without any thought of this future use in
> > mind and in all of them I have something like
> >
> > from pylab import figure, cla, clf, plot, semiliogx, show, ...
> >
> > at the top.  This makes them completely incompatible with embedding in
> > a WX application.  So, I need to re-write them and I want to know how
> > to do that best.  John had some suggestions and I had some new
> > questions as I tried to act on his thoughts.  So, the actual plotting
> > functions don't have to be re-useable in both contexts, but it would
> > be nice.
> >
> > I can't actually run your code because I don't have the wxmpl.py
> > module.  Looking at it, it looks like a really nice set of functions
> > that work cleanly with embedding in a backend.  How could I call one
> > of the functions from the command line?  Could I do something like:
> > import plotting, pylab
> > myfig = pylab.figure()
> > plotting.plot_simple(myfig)
> >
> > and would I need any additional commands to actually show the figure?
> >
> > Let me know if that makes sense and please send me the wxmpl.py file
> > or let me know where I can get it.
> >
> > Thanks again,
> >
> > Ryan
> >
> > On 3/19/07, Ken McIvor <mc...@ii...> wrote:
> > > Ryan,
> > >
> > > In my (limited) experience, it's dicey to mix pylab's plotting
> > > functionality and the OO API.  I guess I'm a little unclear exactly
> > > what your use case is for this.  It sounds like you're goal is to
> > > create a library of functions that operate on Figure instances,
> > > perhaps so you can use them both interactively and as part of a
> > > wxPython application.
> > >
> > > If that's the case, I'd recommend you try using pylab's gcf() and draw
> > > () to acquire and redraw the current Figure instance from within
> > > IPython.  You can also save the return value of pylab's figure(),
> > > which returns a Figure that's already been attached to the
> > > appropriate renderer.  This way you can use the OO API for plotting
> > > without having to futz with the drawing machinery directly.
> > >
> > > This script might give you some ideas about how to structure your
> > > code.  It contains several of the MPL examples re-coded as functions
> > > that accept a Figure instance and use the OO API for plotting.
> > >
> > >         http://svn.csrri.iit.edu/mr-software/wxmpl/trunk/demos/plotting.py
> > >
> > > Ken
> > >
> >
>

[Matplotlib-users] Scrollbars and subplots..

[lazardo <mas...@ya...>]

I'm curious .. how can we include a scrollbar with a subplot, instead of the back and front arrows to view the subplot. Googling matplotlib+scrollbar+subplot brings up a very few results, so I guess it hasn't been attempted before.
 
 Any ideas ? 
 
 Thanx.
 iyer
 
 
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