matplotlib-users

[Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Nils W. <nw...@me...>]

Hi all,

How do I use \frac{a}{b} within labels ?

from pylab import *
from scipy import *
x = linspace(0,pi,20)
plot(x,sin(x))
title(r'\frac{\Theta}{2\pi}')
xlabel(r'\frac{\Theta}{2\pi}')  # The output is not o.k.
show()

Am I missing something or is it a bug ?

matplotlib data path /usr/lib64/python2.4/site-packages/matplotlib/mpl-data
$HOME=/home/nwagner
CONFIGDIR=/home/nwagner/.matplotlib
ghostscript-8.15 found. ghostscript-8.16 or later is recommended for use
with the text.usetex option.
loaded rc file /home/nwagner/.matplotlib/matplotlibrc
matplotlib version 0.87.1
verbose.level helpful
interactive is False
platform is linux2
numerix numpy 0.9.6.2206
font search path ['/usr/lib64/python2.4/site-packages/matplotlib/mpl-data']
loaded ttfcache file /home/nwagner/.matplotlib/ttffont.cache
backend GTKAgg version 2.8.0

Nils

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Christian M. <mee...@un...>]

Hoi,


On Wednesday 08 March 2006 11:06, Nils Wagner wrote:
> title(r'\frac{\Theta}{2\pi}')
> xlabel(r'\frac{\Theta}{2\pi}')  # The output is not o.k.

And the writing the title is working? Try
 xlabel(r'$\frac{\Theta}{2\pi}$')
instead.

Hope this helps.

Christian

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Darren D. <dd...@co...>]

>> On Wednesday 08 March 2006 5:06 am, Nils Wagner wrote:
>> =A0=20
>>> Hi all,
>>>
>>> How do I use \frac{a}{b} within labels ?
>>>
>>> from pylab import *
>>> from scipy import *
>>> x =3D linspace(0,pi,20)
>>> plot(x,sin(x))
>>> title(r'\frac{\Theta}{2\pi}')
>>> xlabel(r'\frac{\Theta}{2\pi}') =A0# The output is not o.k.
>>> show()
>>>
>>> Am I missing something or is it a bug ?
>>> =A0 =A0=20
>>
>> What does "The output is not o.k." mean?
>> =A0=20
> The output is somewhat like \Theta \frac{}{2\pi}
> If I use
> xlabel(r'$\frac{\Theta}{2\pi}$')
>
> it works fine.

This is not a bug. Please keep in mind that usetex is really only an interf=
ace=20
to latex. For problems specific to LaTeX, it would be best to consult the=20
appropriate sources or lists. As it happens, \frac is only allowed in math=
=20
mode. That it produced any output at outside of mathmode is a case of faili=
ng=20
silently.

Does anyone know how to catch exit status using os.popen and friends? LaTeX=
=20
would have returned an exit status of 1 for this example, which could be us=
ed=20
to raise a warning.

Darren

[Matplotlib-users] Re: Displaying \frac{a}{b} in xlabel

[Jouni K S. <jk...@ik...>]

Darren Dale <dd...@co...> writes:

> Does anyone know how to catch exit status using os.popen and
> friends? LaTeX would have returned an exit status of 1 for this
> example, which could be used to raise a warning.

I think you should get the exit status from the close() method, and 
http://docs.python.org/lib/os-newstreams.html
seems to confirm this. Strangely, popen2 etc do not allow you to get
the exit status.

-- 
Jouni

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

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

I think I got it.  I had to play around a bit with a couple different
approaches.  Part of the trick is that you have to run latex with
-interaction=3Dnonstopmode, otherwise the child process never completes
and it seems like most of python's tools for capturing the errors and
outputs just hang.

Here is what I did:
import popen2
In [8]: latexcmd3=3Dpopen2.Popen3('latex -interaction=3Dnonstopmode bad.tex=
')

In [9]: latexcmd3.wait()
Out[9]: 256

In [10]: latexcmd4=3Dpopen2.Popen3('latex -interaction=3Dnonstopmode good.t=
ex')

In [11]: latexcmd4.wait()
Out[11]: 0

where bad.tex and good.tex basically have just headers and
\frac{1}{\theta} with and without $$ around it.  If I just use
os.popen3, the stderr object returned is empty in both cases:

In [14]: r,w,e=3Dos.popen3('latex -interaction=3Dnonstopmode good.tex')

In [15]: e.readlines()
Out[15]: []

In [16]: r,w,e=3Dos.popen3('latex -interaction=3Dnonstopmode bad.tex')

In [17]: e.readlines()
Out[17]: []

and to know there was a problem, you would have to parse w.readlines()
- and in this case it doesn't even say there is an error, it mentions
something about a missing $.

But it seems like creating your own Popen3 object and executing it
through the wait() command, returns 0 on a clean exit or 256 on the
bad ones (at least for this error).  I have compiled one other good
file from my hard drive and it also returns 0.

Hope this helps,

Ryan

On 3/8/06, Darren Dale <dd...@co...> wrote:
> >> On Wednesday 08 March 2006 5:06 am, Nils Wagner wrote:
> >>
> >>> Hi all,
> >>>
> >>> How do I use \frac{a}{b} within labels ?
> >>>
> >>> from pylab import *
> >>> from scipy import *
> >>> x =3D linspace(0,pi,20)
> >>> plot(x,sin(x))
> >>> title(r'\frac{\Theta}{2\pi}')
> >>> xlabel(r'\frac{\Theta}{2\pi}') # The output is not o.k.
> >>> show()
> >>>
> >>> Am I missing something or is it a bug ?
> >>>
> >>
> >> What does "The output is not o.k." mean?
> >>
> > The output is somewhat like \Theta \frac{}{2\pi}
> > If I use
> > xlabel(r'$\frac{\Theta}{2\pi}$')
> >
> > it works fine.
>
> This is not a bug. Please keep in mind that usetex is really only an inte=
rface
> to latex. For problems specific to LaTeX, it would be best to consult the
> appropriate sources or lists. As it happens, \frac is only allowed in mat=
h
> mode. That it produced any output at outside of mathmode is a case of fai=
ling
> silently.
>
> Does anyone know how to catch exit status using os.popen and friends? LaT=
eX
> would have returned an exit status of 1 for this example, which could be =
used
> to raise a warning.
>
> Darren
>
>
> -------------------------------------------------------
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>

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Andrew S. <str...@as...>]

Hi Darren,

>Does anyone know how to catch exit status using os.popen and friends?
>
You may want to switch to subprocess.py. It comes with Python 2.4, but
it's backwards compatible with Python2.3 (maybe older). We could just
include it alongside the modules that want to use it. It's pretty easy
to use and is meant to unify all the various ways of executing a subprocess.

Here's an example from some other code of mine (a recursive build tool
that seeks out directories with setup.py and builds them with
setuptools). It should be a good example of using subprocess.

    args = [sys.executable,'-c',"import setuptools; execfile('setup.py')"]
    args.extend(commands)
           
    print dir,':',' '.join(args)
    sub = subprocess.Popen(args,
                           cwd=dir,
                           stdout=subprocess.PIPE,
                           stderr=subprocess.PIPE,
                           )
    sub.wait()
    if sub.returncode != 0:
        print '-='*20
        print '*** The following call failed:'
        print args
        stdout = sub.stdout.read()
        if len(stdout):
            print '*** stdout was:'
            print stdout
        stderr = sub.stderr.read()
        if len(stderr):
            print '*** stderr was:'
            print stderr
        print '-='*20
        sys.exit( sub.returncode )

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Darren D. <dd...@co...>]

On Wednesday 08 March 2006 12:07, you wrote:
> Hi Darren,
>
> >Does anyone know how to catch exit status using os.popen and friends?
>
> You may want to switch to subprocess.py. It comes with Python 2.4, but
> it's backwards compatible with Python2.3 (maybe older). 

Thank you for the suggestion. How is it compatible with Python-2.3? Do you 
mean we would include the source for that module in mpl?

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Andrew S. <str...@as...>]

Darren Dale wrote:

>On Wednesday 08 March 2006 12:07, you wrote:
>  
>
>>Hi Darren,
>>
>>    
>>
>>>Does anyone know how to catch exit status using os.popen and friends?
>>>      
>>>
>>You may want to switch to subprocess.py. It comes with Python 2.4, but
>>it's backwards compatible with Python2.3 (maybe older). 
>>    
>>
>
>Thank you for the suggestion. How is it compatible with Python-2.3? Do you 
>mean we would include the source for that module in mpl?
>  
>
Yes, exactly.

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

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

>>>>> "Darren" == Darren Dale <dd...@co...> writes:
    Darren> Thank you for the suggestion. How is it compatible with
    Darren> Python-2.3? Do you mean we would include the source for
    Darren> that module in mpl?

Yep, just as we include pyparsing, et al.

JDH

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Eric F. <ef...@ha...>]

John,

John Hunter wrote:
>>>>>>"Darren" == Darren Dale <dd...@co...> writes:
> 
>     Darren> Thank you for the suggestion. How is it compatible with
>     Darren> Python-2.3? Do you mean we would include the source for
>     Darren> that module in mpl?
> 
> Yep, just as we include pyparsing, et al.
> 
> JDH


What about Python-2.2?  Do we still need to stay compatible with that? 
I would be happy to see that go, and officially move the requirement up 
to 2.3, if this has not already been done.

Eric

Re: [Matplotlib-users] Displaying \frac{a}{b} in xlabel

[Darren D. <dd...@co...>]

On Wednesday 08 March 2006 13:10, Eric Firing wrote:
> John,
>
> John Hunter wrote:
> >>>>>>"Darren" == Darren Dale <dd...@co...> writes:
> >
> >     Darren> Thank you for the suggestion. How is it compatible with
> >     Darren> Python-2.3? Do you mean we would include the source for
> >     Darren> that module in mpl?
> >
> > Yep, just as we include pyparsing, et al.
> >
> > JDH
>
> What about Python-2.2?  Do we still need to stay compatible with that?
> I would be happy to see that go, and officially move the requirement up
> to 2.3, if this has not already been done.

I have posted subprocess.py at 
http://staff.chess.cornell.edu/~dale/matplotlib/subprocess.py

running python subprocess.py will execute a test, which I tried with python 
2.2 and 2.3 on linux. They both seemed to work. A successful test includes 
failing to open a bogus file and therefore raising an exception as the last 
step. Would anyone running python-2.3 or 2.2 on windows or mac run this test 
and report the result?

Thanks,
Darren