advice on writing an application

Community matplotlib-users
1

Hi,
I'm in the way of rewriting in Python from scratch an old matlab data
analysis program for AFM data. The program should have a quite simple
GUI with a graph capable of interactive plotting (i.e. clicking on two
points on a 2d graph and fitting the points in between) and a couple of
buttons/menus for fit options and graph options. It's a couple of days
I'm learning matplotlib/pylab and scipy, and they seem powerful enough
to fulfill my needs.

Now, my dream would be to embed matplotlib in a full WxPython
application, instead of using pylab, but (1)I have read that it requires
to rewrite some basic pylab facilities, like taking plot coordinates of
the mouse, that I really need and that's very easy to use (2)I still
have to learn WxPython, and even if I'd eventually do it, it seems messy to me to learn WxPython and to embed matplotlib in it at the same time (3)I have not so much time...I have to analyze that data, more sooner than later. :frowning: I think I'll eventually do an embedded matplotlib application, but I'd like to think about it as "version 2.0".

So, there are two solutions that I'm considering:
- Using WxMpl or MPlot. What are pros and cons of both wrappers?
- Creating a small, pure WxPython application that calls pylab to manage graph operations. I think it would look somehow like Gimp, with a tall and thin window full of buttons, menus etc. and the graph as a separate pylab window.

What's the best alternative and/or your advice and critics about it?

Thanks,
Massimo

···

--
Massimo Sandal
University of Bologna
Department of Biochemistry "G.Moruzzi"

snail mail:
Via Irnerio 48, 40126 Bologna, Italy

email:
massimo.sandal@...898...

tel: +39-051-2094388
fax: +39-051-2094387

2

massimo sandal wrote:

Now, my dream would be to embed matplotlib in a full WxPython
application, instead of using pylab

That is probably a good way to go.

but (1)I have read that it requires to rewrite some basic pylab facilities

As any of us write them, we need to contribute them back to MPL, so that one day, everything will be in the OO interface. there will always be a couple extra things, like managing where to put your MPL window, but you'd want to control that anyway in an embedded app.

It seems messy to me to learn WxPython and to embed matplotlib in it at the same time

You are right that that is a bit of a project.

So, there are two solutions that I'm considering:
- Using WxMpl or MPlot.

I would say to use one of these for sure.

What are pros and cons of both wrappers?

I'd love to see this too. It would be great if we could standardize on one, full featured, wxMPL solution.

- Creating a small, pure WxPython application that calls pylab to manage graph operations.

The issue is that pylab expects to manage it's own Frame. You can't have two wxPython applications in one process, so they will collide, unless you are talking about running a pylab instance in a separate process. That would require some kind of inter-process communication, which would be more work than figuring out how to embed MPL in wx.

-Chris

···

--
Christopher Barker, Ph.D.
Oceanographer
                                         
NOAA/OR&R/HAZMAT (206) 526-6959 voice
7600 Sand Point Way NE (206) 526-6329 fax
Seattle, WA 98115 (206) 526-6317 main reception

Chris.Barker@...259...

3

Chris,

but (1)I have read that it requires to rewrite some basic pylab facilities

As any of us write them, we need to contribute them back to MPL, so that one day, everything will be in the OO interface. there will always be a couple extra things, like managing where to put your MPL window, but you'd want to control that anyway in an embedded app.

I'd surely love to contribute to free software. I'll probably hack
something to cover my needs, but I think contributing back would need to
have things polished and coherent. I don't know if I will manage to do it...
Anyway I'll release all my software publicly under a free license (GPL
probably), and if I put up something of interest for MPL, I will be
happy to discuss it on the MPL-devel mailing list.

About the OO MPL interface, it seems to be a bit lacking in
documentation. Is there some hint you can give me? What important
goodies pylab has that the OO interface has not? I'm expecially
concerned about the rectangular zoom and mapping the mouse position on
the plot, I have quite a need for them.

It seems messy to me to learn WxPython and to embed matplotlib in it at the same time

You are right that that is a bit of a project.

Well, I had a look to the wxpython tutorial in the meantime and happily
it looks easier than I thought before. I have already played with
Tkinter in the past and the underlying logic seems similar. So perhaps
it's not so bad, I'll play a bit with wxpython at home to see how
comfortable I am.

So, there are two solutions that I'm considering:
- Using WxMpl or MPlot.

I would say to use one of these for sure.

What are pros and cons of both wrappers?

I'd love to see this too. It would be great if we could standardize on one, full featured, wxMPL solution.

Hope someone will give us suggestions about these libraries. I'm not
that happy to add another dependency to my project, but reading below it
seems the only way to go.

- Creating a small, pure WxPython application that calls pylab to manage graph operations.

The issue is that pylab expects to manage it's own Frame. You can't have two wxPython applications in one process, so they will collide, unless you are talking about running a pylab instance in a separate process. That would require some kind of inter-process communication, which would be more work than figuring out how to embed MPL in wx.

Ok. This is a bit bad, because it seemed the simplest solution. I
thought that the pylab frame and the wxapp frame could be kept distinct
but interacting in the same app, just being two separate objects.
Thank you a lot, you saved me a lot of time!

Massimo

···

--
Massimo Sandal
University of Bologna
Department of Biochemistry "G.Moruzzi"

snail mail:
Via Irnerio 48, 40126 Bologna, Italy

email:
massimo.sandal@...898...

tel: +39-051-2094388
fax: +39-051-2094387

4

Hello Massimo,

I'm in the way of rewriting in Python from scratch an old matlab data
analysis program for AFM data. The program should have a quite simple
GUI with a graph capable of interactive plotting (i.e. clicking on two
points on a 2d graph and fitting the points in between) and a couple of
buttons/menus for fit options and graph options. It's a couple of days
I'm learning matplotlib/pylab and scipy, and they seem powerful enough
to fulfill my needs.

First of all, why not take a look at an existing solution for AFM:

http://gwyddion.net/

It looks very good and is already very mature. It provides a plugin architecture, a modern graphical interface, is portable and seems to be funded as well. However, it can only analyze surface data, and I don't know if this is what you meant with '2d graph'.

Best regards,

Niklas Volbers.

5

massimo sandal wrote:

Now, my dream would be to embed matplotlib in a full WxPython
application, instead of using pylab

That is probably a good way to go.

I also agree that this is the way to go. If you're going to be putting a lot of effort into the rest of the application, I'd encourage you to go the extra mile and embed matplotlib rather than using pylab. If nothing else, the result will have a more consistent and polished look.

but (1)I have read that it requires to rewrite some basic pylab facilities

If you just embed a FigureCanvasWxAgg you're going to have to write all of the user interaction stuff, like zooming. If you use one of the embedding libraries you get all of that for free.

As any of us write them, we need to contribute them back to MPL, so that one day, everything will be in the OO interface.

You're right, Chris. The only problem is that I see some tension between providing a decent OO API in matplotlib and providing good support for embedding. For example, in WxMpl I chose to favor wxPython's event system over matplotlib's events because I felt it made for a more consistent API for wxPython programmers.

- Creating a small, pure WxPython application that calls pylab to manage graph operations.

The issue is that pylab expects to manage it's own Frame. You can't have two wxPython applications in one process, so they will collide, unless you are talking about running a pylab instance in a separate process.

The problem isn't pylab managing its own wx.Frame, but rather that Pylab used to always try to create its own wx.App. It now checks to see if one already exists, so you can to use pylab from your wxPython application without everything blowing up.

Ken

···

On 11/30/05 11:50, Chris Barker wrote:

6

About the OO MPL interface, it seems to be a bit lacking in
documentation. Is there some hint you can give me?

The EmbeddingInWx cookbook entry includes some good starting points:
  http://www.scipy.org/wikis/topical_software/EmbeddingInWx#ooapi

It links to a bunch of matplotlib examples translated to the OO API:
  http://www.scipy.org/wikis/topical_software/oo-demos.py

What important goodies pylab has that the OO interface has not? I'm
expecially concerned about the rectangular zoom and mapping the mouse position on the plot, I have quite a need for them.

The most important difference is that pylab gives you user interaction features (like zooming and displaying the position) but the OO interface does not. An embedding library will give you those features, plus ones which pylab does not (e.g. printing support, selecting points and regions).

Hope someone will give us suggestions about these libraries.

It's kind of an apples to oranges comparison, because WxMpl and MPlot attempt to solve different problems. MPlot gives you a very high-level interface for creating X/Y plots. WxMpl gives you smarter FigureCanvasWxAgg which can plot anything using matplotlib's OO API.

Since your first email mentioned wanting to pick regions of a plot to fit over, I'd suggest trying out WxMpl. I just released a new version which fixes the point and region picking and includes a demo of it.

Ken

···

On 11/30/05 12:29, massimo sandal wrote:

7

Ken McIvor wrote:

You're right, Chris. The only problem is that I see some tension between providing a decent OO API in matplotlib and providing good support for embedding. For example, in WxMpl I chose to favor wxPython's event system over matplotlib's events because I felt it made for a more consistent API for wxPython programmers.

Hmm. I'm a longtime user of wxPython, and an occasional user of MPL. Given the kind of work I do, it's only a matter of time before I need to embed MPL in wxPython. So I've been keeping an eye on your work, but not really using it.

However, I'd love to have a nice natural way to use MPL in wx, and WxMPL seems to be designed just for that. I think I probably agree with you that using the native wx events make sense. I can imagine a lot of ways in which one would want to integrate MPL-related events with other parts of the application.

-Chris

···

--
Christopher Barker, Ph.D.
Oceanographer
                                         
NOAA/OR&R/HAZMAT (206) 526-6959 voice
7600 Sand Point Way NE (206) 526-6329 fax
Seattle, WA 98115 (206) 526-6317 main reception

Chris.Barker@...259...

8

Dear Massimo,

Sorry I wasn't able to respond sooner. I've been running experiments
all day. As a warning, this response may be long, and I won't take
the time to be overly polite. So let me say it now: Matplotlib is a
great plotting library and John should be knighted.

I was in a similar dilemma a little over a year ago when I was
comfortable enough with matplotlib and its development that I knew it
was what I wanted to commit to using. At that time (late summer
2004), wxmpl did not exist and many of the additions for interactivity
in matplotlib did not exist. I had already decided to abandon
Tkinter/Pmw.BLT plotting, but it took awhile to find a better
solution. Matplotlib is it.

And I definitely wanted (and still want) a wxPython plotting widget
which is intended to go into applications. Much of matplotlib, and
the other responses seem to fail to understand this: I (and I'm
assuming you) want a plotting widget that goes into a wxPython
application. I want to say something not much harder than
      plotpanel = SomeMatplotLibPanel(wx_parent_id)
      plotplanel.plot(x,y)

And then have the user (that is *MY* user -- the person running the
program, not the person writing the script) be able to change the
color, change the titles, zoom in, zoom out, print, save to a PNG.

MPlot tries to do this. For 2-d line plots, it does this fairly well.
It may not be the best code, it certainly could use improvement.
Please feel free to make or suggest changes. If you (or anyone else)
would like to use it or develop it, please let me know how I can help
you. I'd love for it to be improved -- it really needs false color
maps soon. OTOH, if something better comes along, I'll happily use
it.

Pylab is NOT suitable for applications. It assumes that the end user
is someone who uses python. Somehow this became the higher priority
for matplotlib. I think this is a terrible mistake. Seeing so many
examples and questions on this mailing list assuming
    from pylab import *

is really quite sad. To me it suggest this lovely packaged advertised
as a library is not being used as a library at all. Matplotlib is far
too nice to be an add-on to IPython or used only for writing
quick-n-dirty scripts.

wxMPL is definitely a very nice wx wrapping of MPL. My recollection
is that Ken McIvor wrote wxmpl after I showed him MPlot, but I'd defer
to Ken's version of the story. I'm also very happy that Ken's
maintaining the wx backend. I definitely spent most of the effort in
MPlot on bindings, printing, user configuration, and worrying about
being able to 'stripchart' (update a trace at close to 'real time').
I'm sure that some of what I wrote could be replaced with wxmpl or
matplotlib calls at this point. You may understand my reluctance to
do this (like it works and I have my own data to analyze and
applications to write), but I would not be opposed to seeing this
done.

I would also characterize wxMPL as being focused on the
programmer/script writer, not on the end user of an application. So
it's not exactly a 'wxPython Plot Widget'. But it might make the code
of MPlot easier to use/manage/improve.

On using matplotlib bindings and the Navigator toolbars, I'd guess you
don't want to do this. The toolbars are ugly, take up screen real
estate, do stuff you don't need and don't do stuff you do need. I'm
sure these are fine when you're doing a quick-n-dirty plot with an
'ipython -pylab' script, but I somehow never need to do that. Using
the matplotlib bindings would mean separate kinds of event handlers
for a MPL Panel and a non-MPL Panels. I guess that's inevitable, but
I'd still suggest sticking with straight wx.Bind methods. I don't
think the MPL bindings provide anything that can't easily be
reproduced, though it's been awhile since I looked at them.

Since you're short on time (we all are), I suggest giving MPlot a spin
and see if it does enough of what you need. I'd appreciate hearing
what does and doesn't. Finally, I was very happy to see your
response to the fairly silly 'use some other package', and agree
completely with your sentiment.

Cheers,

--Matt

PS: a very short wxPython / MPlot example:

import wx
import MPlot
import matplotlib.numerix as Num

x = Numpy.arange(0.0,10.0,0.1)
y = Numpy.sin(2*x)/(x+2)
app = wx.PySimpleApp()

pframe = MPlot.PlotFrame()
pframe.plot(x,y)
pframe.set_title('Test Plot')
pframe.set_xlabel(r'$R (\angstrom)$')
pframe.write_message('MPlot PlotFrame example: Try Help->Quick Reference')
pframe.Show()
pframe.Raise()
app.MainLoop()

9

Whoa!

Thank you for all your answers. It's one of the most helpful mailing lists I ever joined.

John:
>There is some tutorial documentation, particularly Robert Leftwich's
>tutorial - http://matplotlib.sourceforge.net/leftwich_tut.txt. This
>link recently disappeared (by accident) from the FAQ entry
>http://matplotlib.sf.net/faq.html#OO

Thank you very much (and kudos for your work, by the way: the more I dive into it, the nicer it looks). I already had seen the faq entry, but the little tutorial by Leftwich with the class list just makes me feel better :slight_smile:

Ken:
>An embedding library will give you those features, plus ones which >pylab does not (e.g. printing support, selecting points and regions).

Ok. What I wanted to know is if in pylab there were hard-coded features that the MPL OO interface has not, or if these features were already present in MPL but simply had to be called and merged together by the user (don't know if I'm being clear here - anyway you seem to point it's the second, happier case).

>It now checks to see if one already exists, so you can to use pylab >from your wxPython application without everything blowing up.

Hmm. Evil temptation! But I'm more and more looking at wx embedding,anyway.
Anyway it's nice to know it's an option if someone wants to hack something someday.

Chris:
>Be sure to join the wxpython-users mailing list. They (We) are every >bit as helpful as this group.

I really hope so!

Niklas:
>First of all, why not take a look at an existing solution for AFM:

>http://gwyddion.net/

>It looks very good and is already very mature. It provides a plugin >architecture, a modern graphical interface, is portable and seems to be >funded as well. However, it can only analyze surface data, and I don't >know if this is what you meant with '2d graph'.

I didn't know about it. It seems really a good app, and I just mailed to my collegues if they know about it, it could help in our lab. Alas, (1) I'm all in that odd "force spectroscopy" thing (despite being two years I work with AFM, I never did an image!), and I don't see mention about it (2) I'd prefer to code my app to cover my needs. Who knows if it will be the app of someone else too? I hope to do a good enough work for it. I don't like that much to hack just for myself.
Anyway if you know about good force spectroscopy analysis free software, let me know!

Matt:
>I would also characterize wxMPL as being focused on the
>programmer/script writer, not on the end user of an application. So
>it's not exactly a 'wxPython Plot Widget'. But it might make the code
>of MPlot easier to use/manage/improve.

I don't grasp what do you want to mean... if wxMPL is a wx interface for MPL, it seems focusing on the end user is the programmer's task, isn't it? and it seems right to me. In which sense is MPlot more "focused on the end user"? and what do you mean with "wxMPL is not exactly a 'wxpython plot widget'"?

>On using matplotlib bindings and the Navigator toolbars, I'd guess you
>don't want to do this. The toolbars are ugly, take up screen real
>estate, do stuff you don't need and don't do stuff you do need.

I agree toolbars are not essential, but they're nice IMHO. I don't strictly need them, except for the panning and zooming tools. Hope they're not hard to reproduce, should I have a look at the pylab code?). For the bindings, yes, I'd really like consistency between the graphic toolkit and MPL.

>Finally, I was very happy to see your
>response to the fairly silly 'use some other package', and agree
>completely with your sentiment.

Well, he just tried to be helpful.

Anyway, after having heard both developers, I'm still confused about what to use, if wxMPL or MPlot... I think I'll give wxMPL a try, first.

Thank you all for your long and informative answers. It's a bless to have both the MPL, wxMPL and MPlot developers being here to help me, along with such experienced and friendly users.
It's two years I use almost exclusively free software, and nevertheless the both technical and human wonders of it don't cease to amaze me. Thank you all.

Massimo

···

--
Massimo Sandal
University of Bologna
Department of Biochemistry "G.Moruzzi"

snail mail:
Via Irnerio 48, 40126 Bologna, Italy

email:
massimo.sandal@...898...

tel: +39-051-2094388
fax: +39-051-2094387

10

Massimo,

Matt:
>I would also characterize wxMPL as being focused on the
>programmer/script writer, not on the end user of an application. So
>it's not exactly a 'wxPython Plot Widget'. But it might make the code
>of MPlot easier to use/manage/improve.

I don't grasp what do you want to mean... if wxMPL is a wx interface for
MPL, it seems focusing on the end user is the programmer's task, isn't
it? and it seems right to me. In which sense is MPlot more "focused on
the end user"? and what do you mean with "wxMPL is not exactly a
'wxpython plot widget'"?

Here's what I think the fundamental differences are. Maybe Ken can
give an opinion too.

wxMPL gives a nice and relatively complete set of tools with which you
can build any MPL functionality into a wxPython application. You'll
have to do some MPL-aware programming with wxMPL to get it to do what
you want. Like (correct me if I'm wrong, Ken), you'll have to
explicitly enable/disable zooming, and add your own GUI controls for
having user-set titles and such, and know that to plot, you need to
get the axes from the figure and use axes.plot(). I believe there
is no user-level way for altering the plots made with wxMPL.

In contrast, MPlot provides a PlotPanel and PlotFrame that already
have bindings for zooming, picking coordinates, and so on built in,
has a plot() method of its own, and also provides a GUI form (from a
pop-up menu that shows up on right-click) for users to change plot
titles, placement of legend, font sizes, and symbol and line types and
colors for the different 2D traces. To do this, MPlot does make
forced choices for bindings -- zooming is by dragging a rubberband
box, coordinates show up only on left-click, etc (I believe that wxMPL
also makes similar forced choices. This greatly reduces the need
for mpl-aware coding. You simply say
        self.plotframe = MPlot.PlotFrame(self)
        self.plotframe.Show()
        self.plotframe.plot(xdata,ydata)

you don't need to worry about bindings or making a form for the user
to change the plot titles or colors or use the matplotlib OO API at
all. MPlot takes care of that, or tries to anyway.

if wxMPL is a wx interface for MPL, it seems focusing on the end user is the programmer's
task, isn't it? and it seems right to me

With wxMPL it is, and wxMPL gives tools to programmer to make
applications. With MPlot, much of what you'd want is already built
in: it is a plotting component ready to be put into an application.
You could write your own wxHTML widget yourself too, or you could use
the one that already exists. It's simply a question of using
pre-existing packaged solutions or rolling your own from lower-level
parts.

In which sense is MPlot more "focused on the end user"?

MPlot provides user-level control of plot characteristics (line type,
color, symbol type, titles) with a GUI form and a reasonably complete
set of functionality (printing, saving, etc). Just creating a MPlot
PlotPanel provides all that functionality.

and what do you mean with "wxMPL is not exactly a 'wxpython plot widget'"?

Well, I'd say it's a class library from which one can build wxPython
plotting widgets.

Personally, I want a wxPython plotting widget that is a little further
removed from the underlying plotting library but is also pretty
feature heavy. I don't want to have to use the low-level
matplotlib API to say in a wxPython Program: 'make a wxPlotter', and
'plot x,y to the wxPlotter'. I looked closely at wxPyPlot when I wrote
MPlot (and I had a similar wrapping of BLT that I've used -- really, a
consistent interface is highly useful and easy on users). I wanted
something at a high enough level that knowledge of matplotlib is not
necessary for an enduser to use a PlotPanel, or even for a wxPython
programmer to use it in a program. In my opinion, MPlot ends up
looking a lot better than wxPyPlot -- all because of matplotlib.

Hope that helps, and that Ken (or anyone else) can clear up anything
I've got wrong.

--Matt

11

Ken:
>An embedding library will give you those features, plus ones which >pylab does not (e.g. printing support, selecting points and regions).

Ok. What I wanted to know is if in pylab there were hard-coded features that the MPL OO interface has not, or if these features were already present in MPL but simply had to be called and merged together by the user (don't know if I'm being clear here - anyway you seem to point it's the second, happier case).

I think I understand the question now. I thought you were worried about interactive plotting features, but I now believe you're asking about plotting in general (please correct me if I'm wrong!).

In terms of plotting, etc, I can't think of anything that pylab can do that you can't do using the OO API. You sometimes have to do a bit more work (because pylab manages a lot of details for you), but I haven't ran into any major problems. Of course, I'm using about one tenth of matplotlib's capabilities in my day-to-day work (plot(), imshow(), pcolor()), so you're milage may vary slightly. :slight_smile:

>On using matplotlib bindings and the Navigator toolbars, I'd guess you
>don't want to do this. The toolbars are ugly, take up screen real
>estate, do stuff you don't need and don't do stuff you do need.

I agree toolbars are not essential, but they're nice IMHO. I don't strictly need them, except for the panning and zooming tools. Hope they're not hard to reproduce, should I have a look at the pylab code?).

Here are the toolbar classes:
WX backend -- matplotlib.backends.backend_wx.NavigationToolbar2Wx
WXAgg backend -- matplotlib.backends.backend_wxagg.NavigationToolbar2WxAgg

NavigationToolbar2WxAgg just overrides the "get_canvas(fig, frame)" method to return a FigureCanavsWXAgg, so you'll want to look at NavigationToolbar2Wx if you're interested in how it works.

The following files in the "examples/" subdirectory of the source distribution make use of a WX toolbar. They should help you get started, if you choose to go that route.

  dynamic_demo_wx.py
  dynamic_image_wxagg2.py
  embedding_in_wx2.py
  embedding_in_wx4.py
  wxcursor_demo.py

Ken

···

On 12/01/05 04:43, massimo sandal wrote:

12

Here's what I think the fundamental differences are. Maybe Ken can
give an opinion too.

My take on things is that WxMpl and MPlot solve two different problems. WxMpl is intended to be a FigureCanvasWxAgg that has some pointy-clicky user interactions (e.g. zoom) built in. I gather that Matt considers it "focused on the programmer/script writer, not on the end user of an application" because it doesn't provide end-users with any means to edit the plot. MPlot lets users interactively change the title, axes labels, etc.

I wrote WxMpl after Matt sent me MPlot 0.7 because I felt that his approach wasn't solving my problem: I was thrilled what matplotlib and wanted *all* of it to Just Work with wxPython. Allowing users to edit plots was less important to me than supporting as many kinds of plots as possible. By focusing on adding user interaction to FigureCanvasWxAgg I was able to support all of matplotlib's OO API in one fell swoop.

Like (correct me if I'm wrong, Ken), you'll have to explicitly
enable/disable zooming, and add your own GUI controls for having user-set
titles and such, and know that to plot, you need to get the axes from the
figure and use axes.plot(). I believe there is no user-level way for
altering the plots made with wxMPL.

Zooming and point-under-cursor are enabled by default. You are correct, WxMpl provides no GUI tools to allow application users to alter plots.

To do this, MPlot does make forced choices for bindings -- zooming is by
dragging a rubberband box, coordinates show up only on left-click, etc (I
believe that wxMPL also makes similar forced choices.

Yep. I've followed the BLT convention of zooming by selection a rectangular area and unzooming by right-clicking.

if wxMPL is a wx interface for MPL, it seems focusing on the end user is the programmer's
task, isn't it? and it seems right to me

With wxMPL it is, and wxMPL gives tools to programmer to make
applications. With MPlot, much of what you'd want is already built
in: it is a plotting component ready to be put into an application. You could write your own wxHTML widget yourself too, or you could use
the one that already exists. It's simply a question of using
pre-existing packaged solutions or rolling your own from lower-level
parts.

As always, there is a trade off involved. In other words, MPlot would be a sensible choice if allowing users to edit their plots is very important. WxMpl makes sense if having access to all of MPL's plotting abilities is very important. Furthermore, there's nothing stopping someone from adding support for more kinds of plots to MPlot or from building a plot editor on top of WxMpl, if they were so inclined.

and what do you mean with "wxMPL is not exactly a 'wxpython plot widget'"?

Well, I'd say it's a class library from which one can build wxPython
plotting widgets.

Well I'd say it's a wxPython plotting widget that lets you build plot editors. I guess it all depends on your definition of "wxPython plotting widget". :slight_smile:

I don't want to have to use the low-level matplotlib API to say in a
wxPython Program: 'make a wxPlotter', and 'plot x,y to the wxPlotter'.

As I said earlier, I think we're trying to solve different problems. I do want to use the low-level matplotlib API, because it's a more flexible and powerful. If necessary, I want to be able to say in a wxPython program "make a wxPlotter and then make two subplots, one a line plot with two embedded axes, the other a histogram and a line plot, and then chain their X axes together".

I wanted something at a high enough level that knowledge of matplotlib is
not necessary for an enduser to use a PlotPanel, or even for a wxPython programmer to use it in a program.

I hadn't considered "end users" when writing WxMpl, on the notion that they weren't going to be writing their own wxPython applications any time soon. That being said, I have added some convenience classes to make WxMpl easier to use for ad hoc plotting.

In my opinion, MPlot ends up looking a lot better than wxPyPlot -- all
because of matplotlib.

Matplotlib is an incredible piece of software. I agree with you, John deserves to be knighted.

Ken

P.S. Since Matt posted a short MPlot example, I figured I should post a short WxMpl counter-example :stuck_out_tongue:

import wxmpl
import matplotlib.cm as cm
import matplotlib.mlab as mlab
import matplotlib.numerix as nx

dx, dy = 0.025, 0.025
x = nx.arange(-3.0, 3.0, dx)
y = nx.arange(-3.0, 3.0, dy)
X,Y = mlab.meshgrid(x, y)
Z = (1- X + X**5 + Y**3)*nx.exp(-X**2-Y**2)

class MyPlotApp(wxmpl.PlotApp):
     ABOUT_TITLE = 'WxMpl Example'
     ABOUT_MESSAGE='Behold! An example!\nCopyright 2005 Yoyodyne Inc'

app = MyPlotApp(title='WxMpl Example')
figure = app.get_figure()
axes = figure.gca()

img = axes.imshow(Z, cmap=cm.jet, extent=(-3, 3, -3, 3))
figure.colorbar(img)
axes.set_title('\(1 \- X \+ X^5 \+ Y^3\)\*e^\{\\/^\{\(\-X^2\-Y^2\)\}\}')
axes.set_xlabel('X Axis')
axes.set_ylabel('Y Axis')

app.MainLoop()

···

On 12/01/05 16:13, Matt Newville wrote: