gnuplot-py-users Mailing List for Gnuplot.py

On 1/31/2009 2:05 PM Matt Ball apparently wrote:
> Is it possible to pass Gnuplot.py some form of a Python lambda  
> expression? I'm looking to plot a variety of functions of 1 variable,  
> which I have lambda expressions for. All I need is basic 2D plotting  
> functionality beyond that.

A lambda expression creates a function instance.
You can pass it like any function.  E.g.,
http://gnuplot-py.sourceforge.net/doc/Gnuplot/funcutils.html

Alan Isaac

Is it possible to pass Gnuplot.py some form of a Python lambda  
expression? I'm looking to plot a variety of functions of 1 variable,  
which I have lambda expressions for. All I need is basic 2D plotting  
functionality beyond that.

Matt

[I re-added the mailing list to CC.]

Matt Ball wrote:
> On Jan 24, 2009, at 11:53 PM, Michael Haggerty wrote:
>> Matt Ball wrote:
>>> [...] However, if I run my python script (which uses
>>> gnuplot.py) through x11, I run into two problems: if my gnuplot
>>> constructor does not have the persist=1 option, then the plot window
>>> disappears as soon as it appears.
>>
>> Normally, it should only disappear when the Gnuplot instance is
>> destroyed by your script (for example, if your script ends).  If you
>> keep the Gnuplot instance alive then the window should continue to be
>> displayed.
>>
>>>                                    However, when I do use the
>>> constructor (e.g. as g = Gnuplot.Gnuplot(persist=1)) then the plot
>>> window does persist but it's not interactive!
>>> I don't think that I am asking a lot to have an interactive and
>>> persistent gnuplot window. How can I do this on my Mac? I am perfectly
>>> happy to use something other than AQT or X11 if it gets the job done.
>>
>> This is more of a gnuplot question than a Gnuplot.py question.
> 
> Thanks, Michael. It just seemed like a Gnuplot.py issue because I can
> rotate my plots just fine if I use gnuplot's interactive mode, but not
> if I call it though a python script. I haven't had time to play around
> with using a normal gnuplot script.

I don't know the situation on your platform, but if I start "gnuplot
-persist" under Linux with the default terminal type (which is wxt),
then I can interact with the graphics window even after the gnuplot
command line has been exited.  But if I switch to x11, then I can
interact with the graphics window as long as the command line is active,
but when I exit the command line, then I can't interact with the window
anymore.  So either use a different terminal type, or keep the gnuplot
process running as long as you want to interact with the window.

Michael

Matt Ball wrote:
> [...] However, if I run my python script (which uses  
> gnuplot.py) through x11, I run into two problems: if my gnuplot  
> constructor does not have the persist=1 option, then the plot window  
> disappears as soon as it appears.

Normally, it should only disappear when the Gnuplot instance is
destroyed by your script (for example, if your script ends).  If you
keep the Gnuplot instance alive then the window should continue to be
displayed.

>                                     However, when I do use the  
> constructor (e.g. as g = Gnuplot.Gnuplot(persist=1)) then the plot  
> window does persist but it's not interactive!
> I don't think that I am asking a lot to have an interactive and  
> persistent gnuplot window. How can I do this on my Mac? I am perfectly  
> happy to use something other than AQT or X11 if it gets the job done.  

This is more of a gnuplot question than a Gnuplot.py question.

Michael

Hi,
I am trying to use Gnuplot.py as part of a Python script which I am  
developing on a Mac running Leopard (the latest version). It works  
exactly as expected when I use Aquaterm as my terminal, though  
plotting matrices 100x100 or larger can get very slow. I am trying to  
move away from AQT since it is old and does not support interactive  
viewing, e.g. rotation or zooming. I can start gnuplot itself from  
X11, set the terminal to be x11, and then make pretty plots that are  
fully interactive. However, if I run my python script (which uses  
gnuplot.py) through x11, I run into two problems: if my gnuplot  
constructor does not have the persist=1 option, then the plot window  
disappears as soon as it appears. However, when I do use the  
constructor (e.g. as g = Gnuplot.Gnuplot(persist=1)) then the plot  
window does persist but it's not interactive!
I don't think that I am asking a lot to have an interactive and  
persistent gnuplot window. How can I do this on my Mac? I am perfectly  
happy to use something other than AQT or X11 if it gets the job done.  
Thanks!

Matt

Hi,

I'm getting this error after typing

from scitools.all import *

scitools.easyviz backend is gnuplot
Exception exceptions.AttributeError: "GnuplotProcess instance has no 
attribute 'gnuplot'" in <bound method GnuplotProcess.__del__ of 
<Gnuplot.gp_win32.GnuplotProcess instance at 0x00F0C698>> ignored
Exception exceptions.AttributeError: "Gnuplot instance has no attribute 
'gnuplot'" in <bound method Gnuplot.__del__ of <Gnuplot._Gnuplot.Gnuplot 
instance at 0x00F0C648>> ignored

There is no backtrack, so I don't know where this is happening. It could 
be the fault of scitools.


I configured gp_win32.py like this:
   #     gnuplot_command = r'"C:\Program Files\gp371w32\pgnuplot.exe"'
   #gnuplot_command = r'pgnuplot.exe'
   gnuplot_command = r'C:\python25\gnuplot\bin\pgnuplot.exe' # this file 
exists of course.

I did a dir(self.gnuplot) in gp_win32.py and this variable does exist 
and its methods seems correct.

Including pgnuplot.exe in the PATH variable didn't help.
pgnuplot.exe is launched (I can see it running in the task bar..)

Any suggestions?

Thank you very much,
Best regards,
Ivar Refsdal

Hi,
thanks for the quick answers, I was thinking that it might be some 
float-precision problem. But, being a newbie and as gnuplot.py apparently 
doesn't have a documentation, I couldn't figure it out.

You're right, this type of  precision is probably only interesting for 
physicists and us chemists ;-) And I could probably do with less precision, I 
just haven't bothered to think about if rounding is always a good idea. But 
couldn't there be an auto-detection for the float type or sth? I mean, if 
someone's passing highly precise numbers, he'll probably want to plot them 
correctly...

Could you maybe point me to some information on how to use that workaround? 
I've tried reading the list values as 'np.float64' or converting the list 
via 'np.asarray(x).astype(np.float64)' but that doesn't seem to change 
anything...

Regards,
X.W.

Am Sunday 11 January 2009 17:47:07 schrieb Alan G Isaac:
> On 1/11/2009 11:34 AM Michael Haggerty apparently wrote:
>  > Not Python arrays, but numpy arrays.  The reason this is done is to save
>  > space for huge data sets.  My assumption was that it is unusual to plot
>  > values that vary only in the ninth decimal place.  And since there is a
>  > workaround, it doesn't seem like a bad compromise.
>
> How about letting dtype be an optional argument?
> The default can be np.float32, but the user could
> specify any dtype.
>
> Alan Isaac
>
>
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-- 
Xaver Wurzenberger
Guardinistr. 89
81375 München

Tel.: 089/32163661
Mobil: 0179/4478756

On 1/11/2009 11:34 AM Michael Haggerty apparently wrote:
 > Not Python arrays, but numpy arrays.  The reason this is done is to save
 > space for huge data sets.  My assumption was that it is unusual to plot
 > values that vary only in the ninth decimal place.  And since there is a
 > workaround, it doesn't seem like a bad compromise.


How about letting dtype be an optional argument?
The default can be np.float32, but the user could
specify any dtype.

Alan Isaac

Alan G Isaac wrote:
> On 1/11/2009 9:53 AM Michael Haggerty apparently wrote:
>> The Gnuplot.py library uses float (i.e., single-precision) arrays to
>> store values internally.  When your value is rounded to
>> single-precision, it results in the number that is actually plotted.
> 
> Are you saying it uses the Python array
> module to do this?  This seems a very
> odd decision.  Why not just change that
> to 'double'?

Not Python arrays, but numpy arrays.  The reason this is done is to save
space for huge data sets.  My assumption was that it is unusual to plot
values that vary only in the ninth decimal place.  And since there is a
workaround, it doesn't seem like a bad compromise.

But feel free to change it in your copy :-)

Michael

On 1/11/2009 9:53 AM Michael Haggerty apparently wrote:
> The Gnuplot.py library uses float (i.e., single-precision) arrays to
> store values internally.  When your value is rounded to
> single-precision, it results in the number that is actually plotted.

Are you saying it uses the Python array
module to do this?  This seems a very
odd decision.  Why not just change that
to 'double'?

Alan Isaac

Xaver Wurzenberger wrote:
> I am trying to plot large negative numbers, with 9 digits after the .,  via 
> python (version 2.5.2-3) and python-gnuplot, version 1.8-1 (both Debian Sid 
> packages), on terminal 'dumb', so ascii output.
> But it occurs to me that whenever I plot them from a (float or string) python 
> list (g.plot(Gnuplot.Data(list)), gnuplot is plotting a wrong number. 
> [...]
> 
> list_scf[0][1] is -902.904164954

The Gnuplot.py library uses float (i.e., single-precision) arrays to
store values internally.  When your value is rounded to
single-precision, it results in the number that is actually plotted.

IIRC you can get around this by passing a numpy double array to the
plot() method; I think that the library leaves the values as double
precision in this case.

Michael

Hi,
I'm a newbie to python programming, so I hope this is not a dumb mistake of 
mine ;-)

I am trying to plot large negative numbers, with 9 digits after the .,  via 
python (version 2.5.2-3) and python-gnuplot, version 1.8-1 (both Debian Sid 
packages), on terminal 'dumb', so ascii output.
But it occurs to me that whenever I plot them from a (float or string) python 
list (g.plot(Gnuplot.Data(list)), gnuplot is plotting a wrong number. 
Plotting a file (g.plot(Gnuplot.File('file.plt')) however works. Look at this 
example: I "zoomed in" to the first value here (the ascii formatting is lost 
due to the email, but I think you can see the problem; look at the asterisk 
psoition and y axis numbers!):

(12:55:03)xaver@siduxbox:~/Programme/python$./gw-minimal2.py test_real.log
39 cycles and -902.904164954  Hartree written to list of energies.
5 cycles and -902.912462667  Hartree written to list of energies.
6 cycles and -902.921650947  Hartree written to list of energies.
6 cycles and -902.927426487  Hartree written to list of energies.
6 cycles and -902.930537069  Hartree written to list of energies.
6 cycles and -902.933026922  Hartree written to list of energies.
21 cycles and -902.935555041  Hartree written to list of energies.
6 cycles and -902.937610935  Hartree written to list of energies.
6 cycles and -902.939101838  Hartree written to list of energies.
6 cycles and -902.94003734  Hartree written to list of energies.
6 cycles and -902.94119645  Hartree written to list of energies.
6 cycles and -902.942518852  Hartree written to list of energies.
15 cycles and -902.944932326  Hartree written to list of energies.
6 cycles and -902.947591728  Hartree written to list of energies.
6 cycles and -902.949241052  Hartree written to list of energies.
6 cycles and -902.950658896  Hartree written to list of energies.
6 cycles and -902.951400948  Hartree written to list of energies.
6 cycles and -902.952198923  Hartree written to list of energies.

list_scf is [[39, -902.90416495399995], [44, -902.912462667], 
[50, -902.92165094699999], [56, -902.92742648700005], 
[62, -902.93053706900002], [68, -902.93302692199995], 
[89, -902.93555504100004], [95, -902.93761093499995], 
[101, -902.93910183800006], [107, -902.94003734], [113, -902.94119645000001], 
[119, -902.94251885200003], [134, -902.94493232599996], 
[140, -902.94759172800002], [146, -902.94924105200005], 
[152, -902.95065889600005], [158, -902.95140094800001], 
[164, -902.95219892299997]]

list_scf[0][1] is -902.904164954

                                    Plotting float values:
  Energy/Hartree
   -902.904174810 ++-----+-------+------+-------+------+------+-------+-----++
                  +      +       +      +       +    SCF Optimization +.*..+ +
                  |      :                                                   |
                  |      :                                                   |
   -902.904174808 ++     :                                                  ++
                  |      :                                                   |
                  |      :                                                   |
   -902.904174806 ++     :                                                  ++
                  |      :                                                   |
                  |      *                                                   |
                  |                                                          |
   -902.904174804 ++                                                        ++
                  |                                                          |
                  |                                                          |
   -902.904174802 ++                                                        ++
                  |                                                          |
                  |                                                          |
                  +      +       +      +       +      +      +       +      +
   -902.904174800 ++-----+-------+------+-------+------+------+-------+-----++
                  20     40      60     80     100    120    140     160    
180
                                            Cycles


                                      Plotting plt file:
  Energy/Hartree
   -902.904164960 ++-----+-------+------+-------+------+------+-------+-----++
                  +      +       +      "test_real.log.plt" using 1:2 +.*..+ +
                  |      :                                                   |
                  |      :                                                   |
   -902.904164958 ++     :                                                  ++
                  |      :                                                   |
                  |      :                                                   |
   -902.904164956 ++     :                                                  ++
                  |      :                                                   |
                  |      :                                                   |
                  |      :                                                   |
   -902.904164954 ++     *                                                  ++
                  |                                                          |
                  |                                                          |
   -902.904164952 ++                                                        ++
                  |                                                          |
                  |                                                          |
                  +      +       +      +       +      +      +       +      +
   -902.904164950 ++-----+-------+------+-------+------+------+-------+-----++
                  20     40      60     80     100    120    140     160    
180

Does anyone know what's wrong here?
I can put all files on the net somewhere, if that helps.
Thanks in advance,
X. W.

nit...@gm... wrote:
> For some project of mine I'd like to use dates in Gnuplot.Data and be
> able to use x2 and y2 axes (plot keyword axis).
> 
> Is there any chance these get implemeted soon?

You can, of course, pass arbitrary commands to gnuplot via the Gnuplot
object, so in principle you can do what you want from your own code.
But (particularly for the case of x2/y2) this won't be very convenient.

Gnuplot.py doesn't currently have any active developers, and there
haven't been any new features implemented in quite a while.  So you
shouldn't have high hopes that your wishes will be implemented soon.  If
you want to work on them yourself, I'd be happy to help get you started.
 Or consider offering a bounty to somebody to develop it.

Michael

Hi there,

For some project of mine I'd like to use dates in Gnuplot.Data and be
able to use x2 and y2 axes (plot keyword axis).

Is there any chance these get implemeted soon?

Thanks in advance,
Kai