matplotlib-users Mailing List for matplotlib (Page 9)

I am following up on the discussion of passing a single 2D array to plot.
Wouldn't it make more sense that, in Python array style,
if you give it a single N x K argument you plot rows against the first row?

On the same token, it would be really nice if contour, pcolor and image
take as an x and y argument not only a matrix but just a 1D row. This
should be really easy and would be very useful.

In fact, if more people want it I can submit a patch for the latter one,

Mark



------------------------------
>
> Message: 4
> Date: Wed, 12 Jul 2006 14:38:46 -0400
> From: Alan G Isaac <ai...@am...>
> Subject: Re: [Matplotlib-users] ANN: matplotlib-0.87.4 (bugfix release
>         for     enthon)
> To: mat...@li...
> Message-ID: <Mah...@am...>
> Content-Type: TEXT/PLAIN; CHARSET=ISO-8859-1
>
> On Wed, 12 Jul 2006, Eric Firing apparently wrote:
> > In the single-argument NxK case, I think matlab plots
> > subsequent columns against the first column.  Is this what
> > you would like?
>
> Yes.
>
> Cheers,
> Alan Isaac
>
>

>>>>> "Gregory" =3D=3D Gregory Pi=F1ero <gre...@gm...> writes:

    Gregory> If correct here, I guess I locate the API in the user
    Gregory> guide?  Is there anything else I should be using as a
    Gregory> reference?

http://matplotlib.sourceforge.net/faq.html#OO

http://matplotlib.sourceforge.net/leftwich_tut.txt


JDH

On 7/12/06, John Hunter <jdh...@ac...> wrote:
> In a production app like a web application server generating graphics,
> often times you don't want any magic going on behind the hood, and
> pylab's stateful management of figures, the current figure, and the
> current axes grates on some people who like to have full control over
> object creation and destruction.
>
> So the webapp demo shows how to use the API to manage and use
> figures.  It is mainly a style choice.

Thanks, I'm starting to understand.  So since I am making a web app, I
should be refering to the API reference instead of the screenshots
code:
http://matplotlib.sourceforge.net/screenshots.html

If correct here, I guess I locate the API in the user guide?  Is there
anything else I should be using as a reference?

-Greg

On 7/12/06, John Hunter <jdh...@ac...> wrote:
>
> >>>>> "John" == John Hunter <jdh...@ac...> writes:
>
> >>>>> "David" == David Grant <dav...@gm...> writes:
>     David> edges=[54, 76, 80, 100] stats=[5.423, 23.226, 4.1, 6.93]
>
>
>     John> xticks(edges)
>
> Sorry, what I meant was something like
>
>   xticks(range(len(edges)), ['%d'%edge for edge in edges])
>
> This will set the locations to the integers and the labels to your
> edge labels.



Cool, yeah I think that will work just fine. I don't think I saw xticks in
the matplotlib PDF document I was looking at. What's the best source of
documentation? I just noticed it is here:
http://matplotlib.sourceforge.net/pylab_commands.html which is where I
looked originally... I guess I just didn't know what to look for. :-)

p.s. any idea why [matplotlib-users] didn't show up in the subject line of
my post?

-- 
David Grant
Please Note my new email address: dav...@gm...

>>>>> "David" == David Grant <dav...@gm...> writes:
    David> Cool, yeah I think that will work just fine. I don't think
    David> I saw xticks in the matplotlib PDF document I was looking
    David> at. What's the best source of documentation? 

help(pylab)

JDH

>>>>> "Gregory" =3D=3D Gregory Pi=F1ero <gre...@gm...> writes:

    Gregory> So my only remaining point of confusion is why wasn't the
    Gregory> pylab interface used in the demo here:
    Gregory> http://matplotlib.sourceforge.net/examples/webapp_demo.py

    Gregory> Is it just a style choice?

pylab manages figures for you -- you want to be sure in an application
that creates many figures and saves them to images (like a web app)
that every figure that is created is closed

  fig =3D figure(1)

  ...later
  close(1)

In a production app like a web application server generating graphics,
often times you don't want any magic going on behind the hood, and
pylab's stateful management of figures, the current figure, and the
current axes grates on some people who like to have full control over
object creation and destruction.

So the webapp demo shows how to use the API to manage and use
figures.  It is mainly a style choice.

JDH

So my only remaining point of confusion is why wasn't the pylab
interface used in the demo here:
>     Gregory> http://matplotlib.sourceforge.net/examples/webapp_demo.py

Is it just a style choice?

>>>>> "Gregory" =3D=3D Gregory Pi=F1ero <gre...@gm...> writes:

    Gregory> Hi guys, Is this possible?  Specifically I'm trying
    Gregory> implement something close to this example:
    Gregory> http://matplotlib.sourceforge.net/examples/webapp_demo.py

    Gregory> But would like to be able to utilize code found in
    Gregory> samples like this:
    Gregory> http://matplotlib.sourceforge.net/screenshots/pie_demo.py

You just have to tell matplotlib to use Agg as your backend -- pylab
will respect the default backend, whether it is a GUI, Agg or PS.

There are several ways to choose the backend

  * make it permanent by setting your backend to 'Agg' in matplotlibrc

  * change it on a per script basis exterally by launching with the -d
    option

     > python myscript.py -dAgg
     > python myscript.py -dPS
     > python myscript.py -dGTKAgg

  * probably best for a web app, use the matplotlib "use directive".
    This must be done *before* importing pylab

    import matplotlib
    matplotlib.use('Agg')
    import pylab
    plot and save....

This is discussed at http://matplotlib.sf.net/backends.html

JDH

Hi guys,

Is this possible?  Specifically I'm trying implement something close
to this example:
http://matplotlib.sourceforge.net/examples/webapp_demo.py

But would like to be able to utilize code found in samples like this:
http://matplotlib.sourceforge.net/screenshots/pie_demo.py

Much thanks!

--=20
Gregory Pi=F1ero
Chief Innovation Officer
Blended Technologies
(www.blendedtechnologies.com)

>>>>> "John" == John Hunter <jdh...@ac...> writes:

>>>>> "David" == David Grant <dav...@gm...> writes:
    David> edges=[54, 76, 80, 100] stats=[5.423, 23.226, 4.1, 6.93]


    John> xticks(edges)

Sorry, what I meant was something like

  xticks(range(len(edges)), ['%d'%edge for edge in edges]) 

This will set the locations to the integers and the labels to your
edge labels.

JDH

>>>>> "David" == David Grant <dav...@gm...> writes:

    David> edges=[54, 76, 80, 100] stats=[5.423, 23.226, 4.1, 6.93]


xticks(edges) 

perhaps?

Or maybe I still don't understand.

A complete script might help...

JDH

On 7/12/06, John Hunter <jdh...@ac...> wrote:
>
> >>>>> "David" == David Grant <dav...@gm...> writes:
>
>     David> Anyone know what happened to
>     David> matplotlib.ticker.IndexFormatter? Is there are replacement
>     David> for it?
>
> I don't know -- I don't see anything in the changelog or in the svn
> log.  What did it do, and what version of mpl had it?  Sorry, but my
> memory is failing here...  I don't see any IndexFormatter as far back
> as 0.83.  There is an index locator however....


I managed to accomplish what I wanted to do, using the FuncFormatter I
think... Here's what I was doing. I am plotting results of graphs, graphs
which have a certain number of edges. So I wanted to plot some statistic vs.
number of edges. But the number of edges was not varied in a linear way but
I have a list of which edges. So:

edges=[54, 76, 80, 100]
stats=[5.423, 23.226, 4.1, 6.93]

So basically I wanted t=arange(len(stats) as my x-axis but edges for the
labels (but only if it lies on a major tic). So I did:

    majorFormatter = ticker.FuncFormatter(lambda x, pos: labels[int(x)])
    axis.xaxis.set_major_formatter(majorFormatter)

If anyone knows a better way I would love to know. I'm just learning
matplotlib (I'm a former matlab user) and would love to master it.

-- 
David Grant
Please Note my new email address: dav...@gm...

On Wed, 12 Jul 2006, Eric Firing apparently wrote:=20
> In the single-argument NxK case, I think matlab plots=20
> subsequent columns against the first column.  Is this what=20
> you would like?=20

Yes.

Cheers,
Alan Isaac

Alan G Isaac wrote:
> On Wed, 12 Jul 2006, Stefan van der Walt apparently wrote:=20
>=20
>>It would be useful to have plot accept a 2-D array as well.  Would=
=20
>>patches for this be considered, or is there some reason why this ca=
n't=20
>>work?  At the moment, doing=20
>>P.plot(z) where z is Nx2=20
>=20
>=20
> If 2-D is allowed,
> I hope N=D7K is allowed,
> not just N=D72.

I have thought about this, but haven't gotten around to doing it.  To=
 do=20
the whole job, we could handle a single NxK argument, and we could al=
so=20
handle pairs:
Nx1, NxK
NxK, Nx1
NxK, NxK

I think it is clear what the behavior should be with any of the pairs=
;=20
essentially they should be broadcast to the NxK, NxK case, resulting =
in=20
K lines.

In the single-argument NxK case, I think matlab plots subsequent colu=
mns=20
against the first column.  Is this what you would like?  The alternat=
ive=20
would be to plot each column against the row index, which is what=
=20
happens in the Nx1 case, but I suspect the matlab-compatibility argum=
ent=20
wins out here.  Also, this maintains consistency with the original=
=20
request for Nx2, which I assume was for plotting the second column=
=20
against the first.  I certainly would not want to have NxK behavior=
=20
change as K goes from 2 to values larger than 2.

Eric

I am trying to map the surface of Saturn's largest moon, Titan for a summer research project.  As a rough draft, I would like to plot the temperature (colored red) at the longitude(x) and latitude(y) coordinates.  My data file is tab delimited in three columns (x,y,T).  I am also missing some x,y locations, which I would like to leave blank.

As a final report, I would like the data point to be able to take on different geometries (circle, hexagon, arbitrary shape, etc) and different sizes as well as be able to overlap with neighboring data points.  Finally, I would like to be able to plot this not on a rectangular cartesion coordinate system, but on a planetographic (global projection) coordinate system.

I've spent two days trying everything from gnuplot, matlab, matplotlib and others trying to do this, but to no avail.  Any suggestions would be very welcomed.

>>>>> "David" == David Grant <dav...@gm...> writes:

    David> Anyone know what happened to
    David> matplotlib.ticker.IndexFormatter? Is there are replacement
    David> for it?

I don't know -- I don't see anything in the changelog or in the svn
log.  What did it do, and what version of mpl had it?  Sorry, but my
memory is failing here...  I don't see any IndexFormatter as far back
as 0.83.  There is an index locator however....

Perhaps you should just tell us what you want to do.

JDH

Anyone know what happened to matplotlib.ticker.IndexFormatter? Is there are
replacement for it?

-- 
David Grant

>>>>> "Michael" == Michael  <mi...@ya...> writes:

    Michael> Hi, I'm new to matplotlib and am very impressed!

Thanks!

    Michael> I have a beginner type question:

    Michael> In interactive mode (using the GtkAgg backend) I'll plot
    Michael> multiple lines on a single subplot. The output got
    Michael> clutterred so I was looking for a pylab command to remove
    Michael> one of the plot lines but could not find any easy way to
    Michael> do this.

    Michael> Is this the case? Do I have to clear the current
    Michael> axes(cla) and replot all my lines minus the line I don't
    Michael> want?

    Michael> Something like this would be nice: line_nbr = 3 # delete
    Michael> third line on the current axes deleteline(line_nbr)


You have two options -- the axes stores the lines in a plain-ol-list,
and you can manipulate that list like any python list

If you know the line number, ie, the i-th line you've added to the
list

  del ax.lines[linenumber]

if you don't know the line number, but have an instance of the line

  
  l, = ax.plot(x, y)
  ax.lines.remove(l)

After you've removed the lines, you'll have to force a figure redraw

In pylab, you can simply call

  draw()

or using the API, use the figure canvas method

  canvas.draw()

The containment relationship is Canvas holds a Figure holds an Axes,
but each child has a pointer to its parent, so if you have access to
an Axes instance

  ax.figure.canvas.draw()

JDH

Hello, um..., P., 

On Wednesday 12 July 2006 03:43, PGM wrote:
> Folks,
> I need your wisdom about ticks labels on ordinates for large numbers
> (>1e4). The default behavior I have (0.87.4) is to display tick labels as
> "%.1f", and write a string "x1e+..." above the top left corner of the
> current axes.
>
> - When using "yaxis.tick_right()", the "x1e..." string stays above the top
> left corner. That becomes an issue when using two different scales. How
> could I force the 'mantissa' string to be on the same side as the axis it
> depends on ?

I'll take care of this, but I will need a few days.

> - How could I change the number of decimals being displayed (for example,
> "%.3f" instead of "%.1f"), while keeping the mantissa string ? (I tried a
> "FormatStrFormatter("%.3f"), it's not what I want. With
> "Funcformatter(lambda x,pos: "%.3f"%(x/1000)))", I lose the mantissa
> string...)

You can write your own custom formatter to do this. You can use 
ticker.ScalarFormatter as a guide.

> - Personally, I'm not keen on "3.0 x1e+4", I prefer "30 x1e+3". Is there a
> way to get that ?

Again, this could be handled by a custom formatter.

> I guess that with a bit of trial/error with FuncFormatter and fig.text, I
> should be able to get what I want, but I wanted to check whether there was
> some easier solutions.

Darren

On Wed, 12 Jul 2006, Stefan van der Walt apparently wrote:=20
> It would be useful to have plot accept a 2-D array as well.  Would=20
> patches for this be considered, or is there some reason why this can't=20
> work?  At the moment, doing=20
> P.plot(z) where z is Nx2=20

If 2-D is allowed,
I hope N=D7K is allowed,
not just N=D72.

Cheers,
Alan Isaac

Hi,

I'm new to matplotlib and am very impressed!

I have a beginner type question:

In interactive mode (using the GtkAgg backend) I'll plot multiple 
lines on a single subplot. The output got clutterred so I was looking 
for a pylab command to remove one of the plot lines but could not find
any easy way to do this. 

Is this the case? Do I have to clear the current axes(cla) and replot all my
lines 
minus the line I don't want?

Something like this would be nice:
   line_nbr = 3 # delete third line on the current axes
   deleteline(line_nbr) 

Thanks, Mike

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

The modules have been imported into the matplotlib repository, and
they are semi-functional.  They still need a lot of work though.
There is a new example, simple3d_oo.py.

- Charlie

On 7/11/06, imcs ee <im...@gm...> wrote:
> what about the mplot3d. (http://www.scipy.org/Cookbook/Matplotlib/mplot3D)
> it works nice under matplotlib0.86.2
> but it can't work under matplotlib 0.87.3(with numpy or numeric).
>
> On 7/12/06, Charlie Moad <cw...@gm...> wrote:
> > On 7/7/06, John Hunter <jdh...@ac...> wrote:
> > >
> > > We'd like to do a bugfix release for the next release of enthought
> > > python, which will include the latest mpl.  Apparently, there is a
> > > problem with 0.87.3 and numpy which has been fixed in svn.
> > >
> > > If there is anything we should wait on, let us know, otherwise we'll
> > > probably try to roll out 0.87.4 early next week.
> > >
> > > Thanks,
> > > JDH
> >
> > http://cheeseshop.python.org/pypi/matplotlib/
> > http://sourceforge.net/project/showfiles.php?group_id=80706
> >
> > ===============================================================
> > 2006-07-11 Released 0.87.4 at revision 2558
> >
> > 2006-07-07 Fixed a usetex bug with older versions of latex - DSD
> >
> > 2006-07-07 Add compatibility for NumPy 1.0 - TEO
> >
> > 2006-06-29 Added a Qt4Agg backend. Thank you James Amundson - DSD
> >
> > 2006-06-26 Fixed a usetex bug. On windows, usetex will prcess
> >           postscript output in the current directory rather than
> >           in a temp directory. This is due to the use of spaces
> >           and tildes in windows paths, which cause problems with
> >           latex. The subprocess module is no longer used. - DSD
> >
> > 2006-06-22 Various changes to bar(), barh(), and hist().
> >           Added 'edgecolor' keyword arg to bar() and barh().
> >           The x and y args in barh() have been renamed to width
> >           and bottom respectively, and their order has been swapped
> >           to maintain a (position, value) order ala matlab. left,
> >           height, width and bottom args can now all be scalars or
> >           sequences. barh() now defaults to edge alignment instead
> >           of center alignment. Added a keyword arg 'align' to bar(),
> >           barh() and hist() that controls between edge or center bar
> >           alignment. Fixed ignoring the rcParams['patch.facecolor']
> >           for bar color in bar() and barh(). Fixed ignoring the
> >           rcParams['lines.color'] for error bar color in bar()
> >           and barh(). Fixed a bug where patches would be cleared
> >           when error bars were plotted if rcParams['axes.hold']
> >           was False. - MAS
> >
> > 2006-06-22 Added support for numerix 2-D arrays as alternatives to
> >           a sequence of (x,y) tuples for specifying paths in
> >           collections, quiver, contour, pcolor, transforms.
> >           Fixed contour bug involving setting limits for
> >           color mapping.  Added numpy-style all() to numerix. - EF
> >
> > 2006-06-20 Added custom FigureClass hook to pylab interface - see
> >           examples/custom_figure_class.py
> >
> > 2006-06-16 Added colormaps from gist (gist_earth, gist_stern,
> >           gist_rainbow, gist_gray, gist_yarg, gist_heat, gist_ncar) - JW
> >
> > 2006-06-16 Added a pointer to parent in figure canvas so you can
> >           access the container with fig.canvas.manager.  Useful if
> >           you want to set the window title, eg in gtk
> >           fig.canvas.manager.window.set_title, though a GUI neutral
> >           method would be preferable JDH
> >
> > 2006-06-16 Fixed colorbar.py to handle indexed colors (i.e.,
> >           norm = no_norm()) by centering each colored region
> >           on its index. - EF
> >
> > 2006-06-15 Added scalex and scaley to Axes.autoscale_view to support
> >           selective autoscaling just the x or y axis, and supported
> >           these command in plot so you can say plot(something,
> >           scaley=False) and just the x axis will be autoscaled.
> >           Modified axvline and axhline to support this, so for
> >           example axvline will no longer autoscale the y axis. JDH
> >
> > 2006-06-13 Fix so numpy updates are backward compatible - TEO
> >
> > 2006-06-12 Updated numerix to handle numpy restructuring of
> >           oldnumeric - TEO
> >
> > 2006-06-12 Updated numerix.fft to handle numpy restructuring
> >           Added ImportError to numerix.linear_algebra for numpy -TEO
> >
> > 2006-06-11 Added quiverkey command to pylab and Axes, using
> >           QuiverKey class in quiver.py.  Changed pylab and Axes
> >           to use quiver2 if possible, but drop back to the
> >           newly-renamed quiver_classic if necessary.  Modified
> >           examples/quiver_demo.py to illustrate the new quiver
> >           and quiverkey.  Changed LineCollection implementation
> >           slightly to improve compatibility with PolyCollection. - EF
> >
> > 2006-06-11 Fixed a usetex bug for windows, running latex on files
> >           with spaces in their names or paths was failing - DSD
> >
> > 2006-06-09 Made additions to numerix, changes to quiver to make it
> >           work with all numeric flavors. - EF
> >
> > 2006-06-09 Added quiver2 function to pylab and method to axes,
> >           with implementation via a Quiver class in quiver.py.
> >           quiver2 will replace quiver before the next release;
> >           it is placed alongside it initially to facilitate
> >           testing and transition. See also
> >           examples/quiver2_demo.py. - EF
> >
> > 2006-06-08 Minor bug fix to make ticker.py draw proper minus signs
> >           with usetex - DSD
> >
> >
> > -------------------------------------------------------------------------
> > Using Tomcat but need to do more? Need to support web services, security?
> > Get stuff done quickly with pre-integrated technology to make your job easier
> > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
> > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
> > _______________________________________________
> > Matplotlib-users mailing list
> > Mat...@li...
> > https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> >
>
>
> -------------------------------------------------------------------------
> Using Tomcat but need to do more? Need to support web services, security?
> Get stuff done quickly with pre-integrated technology to make your job easier
> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>

On Tue, Jul 11, 2006 at 10:53:59PM -0400, Charlie Moad wrote:
> 2006-06-22 Added support for numerix 2-D arrays as alternatives to
>            a sequence of (x,y) tuples for specifying paths in
>            collections, quiver, contour, pcolor, transforms.
>            Fixed contour bug involving setting limits for
>            color mapping.  Added numpy-style all() to numerix. - EF

It would be useful to have plot accept a 2-D array as well.  Would
patches for this be considered, or is there some reason why this can't
work?  At the moment, doing

P.plot(z) where z is Nx2,

raises

RuntimeError: xdata and ydata must be the same length

So it doesn't look as though this functionality will override any
current feature.

Regards
St=E9fan

Folks,
I need your wisdom about ticks labels on ordinates for large numbers (>1e4). 
The default behavior I have (0.87.4) is to display tick labels as "%.1f", and 
write a string "x1e+..." above the top left corner of the current axes.

- When using "yaxis.tick_right()", the "x1e..." string stays above the top 
left corner. That becomes an issue when using two different scales. How could 
I force the 'mantissa' string to be on the same side as the axis it depends 
on ?

- How could I change the number of decimals being displayed (for example, 
"%.3f" instead of "%.1f"), while keeping the mantissa string ? (I tried a 
"FormatStrFormatter("%.3f"), it's not what I want. With "Funcformatter(lambda 
x,pos: "%.3f"%(x/1000)))", I lose the mantissa string...)

- Personally, I'm not keen on "3.0 x1e+4", I prefer "30 x1e+3". Is there a way 
to get that ?

I guess that with a bit of trial/error with FuncFormatter and fig.text, I 
should be able to get what I want, but I wanted to check whether there was 
some easier solutions.

Thanks in advance for your help


P.

On 7/11/06, John Hunter <jdh...@ac...> wrote:

> You don't need any defense -- it's no secret that mpl is
> under-documented.  If you know how to look, the information is usually
> there, but the trick is knowing how to look
>
> In [3]: l, = plot([1,2,3])
>
> In [4]: setp(l)

Ah, thanks for that reminder!  That's useful to know/re-know.

> This reminds me -- of late I've been wishing for a grep-like feature
> in ipython
>
>   In [2]: setp(l) | grep dash
>
> to see just the output of setp that matches "dash".  In your case, you
> would have seen
>
>     dash_capstyle: ['butt' | 'round' | 'projecting']
>     dash_joinstyle: ['miter' | 'round' | 'bevel']
>     dashes: sequence of on/off ink in points
>
> suggesting that you can not only configure the dash style, but the
> dash cap and join style as well :-)
>
> Of course, I could add this functionality to setp but it would be more
> generally useful to have it in ipython.
>
> The use case I had in mind today was in history, when I had a bunch of
> commands I wanted to grep through
>
>   In [1000]: history | grep xxx

Yes, I also have wanted something like this.  The problem is that many
utilities don't return anything, they just print to stdout (setp is
one such tool).  Which means that we'd need to capture all of stdout
and have it available for further processing always, in a non-blocking
way (so typing 'ls' doesn't make you wait forever before printing).
This is really pushing ipython far into the shell territory, albeit in
a manner that would be very useful.  I'll forward this to the
ipython-dev list, to see if Ville and Walter (the brains behind the
fancy ipipe) want to pick this ball up and run with it.  I'm now
pretty much only working with Brian on the new branch.

Incidentally, this would bring ipython much closer to Microsoft's
Monad shell model:

    http://arstechnica.com/guides/other/msh.ars

Ever since that review came out, I've thought that python/ipython
already has 90% of those tools, save a proper (but better) pipe-like
model for chaining object results.  With a bit of time investment,
this could certainly be done.

Cheers,

f