matplotlib-users Mailing List for matplotlib (Page 4)

discolemonade, on 2014年08月05日 21:29, wrote:
> Hi,
> 
> I'm using the GTKAgg backend and when I run "import matplotlib.pyplot as
> plt" in the Python shell, I get the _backend_gdk error. I checked all the
> files in my backend and there is no _backend_gdk.py. In fact, there are no
> python modules that start with an underscore.
As a rule of thumb, modules that start with an underscore come
from a compiled C or C++ extension. In this case, the source
file in question lives in src/_backend_gdk.c of the matplotlib
directory.
> It seems that some files were not installed. Is there some kind
> of a gtk dependancy I need to install before installing
> matplotlib? If so, where can I get it? My matplot version is
> 1.3.1. 
Yes, you'll need GTK and its headers installed, something like 
 sudo apt-get install libgtk2.0-dev python-gtk2-dev 
should work on a Debian system, though you should probably just 
 sudo apt-get build-dep python-matplotlib
best,
-- 
 _
 / \
 A* \^ -
 ,./ _.`\\ / \
 / ,--.S \/ \
 / `"~,_ \ \
 __o ?
 _ \<,_ /:\
--(_)/-(_)----.../ | \
--------------.......J
Paul Ivanov
ipython and matplotlib core developer
http://pirsquared.org

Hi,
I'm using the GTKAgg backend and when I run "import matplotlib.pyplot as
plt" in the Python shell, I get the _backend_gdk error. I checked all the
files in my backend and there is no _backend_gdk.py. In fact, there are no
python modules that start with an underscore. It seems that some files were
not installed. Is there some kind of a gtk dependancy I need to install
before installing matplotlib? If so, where can I get it? My matplot version
is 1.3.1. 
thanks
--
View this message in context: http://matplotlib.1069221.n5.nabble.com/ImportError-No-module-named-backend-gdk-tp43753.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Hi all! I'm a bit confused now, since I've never had any problems with bluemarble. The problems have always been in me and how I handle the data, and it probably is like that also this time... But the problem is that bluemarble won't show up, the data seems to plot just fine and so do for example drawcoastlines and drawcountries. Where should I dig into?
import matplotlib.pyplot as plt
from mpl_toolkits.basemap import Basemap
from scipy.io.netcdf import netcdf_file as Dataset
import numpy as np
import pylab
import os
months = [3,45]
for month in months:
 SIT = Dataset('SIT.nc','r')
 
 lons = SIT.variables['lon'][:,:]
 lats = SIT.variables['lat'][:,:]
 masked_SIT = np.ma.masked_where(np.isnan(SIT.variables['sea_ice_thickness'][month,:,:] ), SIT.variables['sea_ice_thickness'][month,:,:] )
 
 m = Basemap(width=5400000*2,height=5400000*2,resolution='l',projection='laea',lat_0=90,lon_0=0)
 fig = plt.figure()
 m.pcolormesh(lons, lats, masked_SIT, latlon = True, vmin=0, vmax=5)
 m.bluemarble(scale=0.5)
 m.drawcoastlines()
 m.drawcountries()
 #m.fillcontinents(color='white')
 cbar = plt.colorbar()
 cbar.cmap.set_over('#ff0066')
 cbar.set_label('SIT [m]', fontsize='x-large')
 plt.title('Sea Ice Thickness %s' % (title), fontsize='x-large')
plt.show()
Cheers, Bill
 		 	 		 

Hi All
I recently wrote a tutorial on how to evaluate and compare colormaps using
perceptual principle. It is geared towards Matplotlib.
http://nbviewer.ipython.org/github/mycarta/tutorials/blob/master/1408_Evaluate_and_compare_colormaps/How_to_evaluate_and_compare_colormaps.ipynb
Although I am a newbie and some of my code may be not all that pythonic
yet, I hope you enjoy the read.
Any feedback would be welcome.
THank you
Matteo

Whoops, I hadn't realized I stumbled onto a clone of sourceforge (a
mirror?). Here is the real link:
http://sourceforge.net/p/matplotlib/mailman/message/188760/
On Sun, Aug 3, 2014 at 9:37 PM, Benjamin Root <ben...@ou...> wrote:
> For those interested, I have found the release announcement that
> introduced the jet colormap:
> http://ehc.ac/p/matplotlib/mailman/message/188760/ . We have someone
> named "Perry" to blame... :-P
>
> Ben Root
>
>
> On Fri, Aug 1, 2014 at 9:01 PM, Benjamin Root <ben...@ou...> wrote:
>
>> Just to keep my notes in one place... from Matplotlib's "Introduction"
>> page is prose that I assume was written by John:
>>
>> For years, I used to use MATLAB exclusively for data analysis and
>> visualization. MATLAB excels at making nice looking plots easy. When I
>> began working with EEG data, I found that I needed to write applications to
>> interact with my data, and developed and EEG analysis application in
>> MATLAB. As the application grew in complexity, interacting with databases,
>> http servers, manipulating complex data structures, I began to strain
>> against the limitations of MATLAB as a programming language, and decided to
>> start over in Python. Python more than makes up for all of MATLAB’s
>> deficiencies as a programming language, but I was having difficulty finding
>> a 2D plotting package (for 3D VTK <http://www.vtk.org/> more than
>> exceeds all of my needs).
>>
>> When I went searching for a Python plotting package, I had several
>> requirements:
>>
>> - Plots should look great - publication quality. One important
>> requirement for me is that the text looks good (antialiased, etc.)
>> - Postscript output for inclusion with TeX documents
>> - Embeddable in a graphical user interface for application development
>> - Code should be easy enough that I can understand it and extend it
>> - Making plots should be easy
>>
>> Finding no package that suited me just right, I did what any
>> self-respecting Python programmer would do: rolled up my sleeves and dived
>> in. Not having any real experience with computer graphics, I decided to
>> emulate MATLAB’s plotting capabilities because that is something MATLAB
>> does very well. This had the added advantage that many people have a lot of
>> MATLAB experience, and thus they can quickly get up to steam plotting in
>> python. From a developer’s perspective, having a fixed user interface (the
>> pylab interface) has been very useful, because the guts of the code base
>> can be redesigned without affecting user code.
>>
>>
>>
>>
>>
>> On Wed, Jul 30, 2014 at 11:51 PM, Benjamin Root <ben...@ou...> wrote:
>>
>>> Fernando,
>>>
>>> This information is going to be the preface of my book on using
>>> matplotlib for making an interactive application (sorry, no IPython, the
>>> editor wanted to keep the scope tight). So, what I am looking for are some
>>> of the major interactive features (who supplied them, and their
>>> reasons/purpose). Also, how has interactive matplotlib supported uses "in
>>> the wild" such as the Mars Phoenix Lander and recently, the ISEE3 reboot
>>> project (that abandoned satellite that was recently revived by citizen
>>> scientists).
>>>
>>> Of, course, any insights to John's original needs/use cases in the early
>>> years would be very valuable as well. I could have sworn he has written
>>> such missives on the mailing lists, but I can't seem to find them.
>>>
>>> Cheers!
>>> Ben Root
>>> On Jul 30, 2014 11:21 PM, "Fernando Perez" <fpe...@gm...> wrote:
>>>
>>>> Hi Ben,
>>>>
>>>> if by interactive plotting you refer to using it interactively via
>>>> ipython and other such systems, there's a good part of that history that is
>>>> spread somewhere between the early mpl and ipython archives AND John's and
>>>> my personal inboxes.
>>>>
>>>> A good chunk of that (not all, mind you, since many others contributed)
>>>> happened with John and I working on it, and sadly he's not with us and I
>>>> had a loss of my early email (anything older than 2005) when I left the
>>>> University of Colorado.
>>>>
>>>> I'd be happy to answer some questions if you have them, to the best of
>>>> my memory. Probably quicker over skype/phone, ping me directly (at my
>>>> Berkeley address) if you want.
>>>>
>>>> Cheers
>>>>
>>>> f
>>>>
>>>>
>>>>
>>>> On Wed, Jul 30, 2014 at 7:20 PM, Benjamin Root <ben...@ou...> wrote:
>>>>
>>>>> Hello all,
>>>>>
>>>>> I am trying to put together notes for a writeup on a short history of
>>>>> matplotlib (in particular, its uses for interactive plotting). I have John
>>>>> Hunter's SciPy 2012 Keynote, which helps, but I was hoping for some other
>>>>> sources.
>>>>>
>>>>> Unfortunately, searching for "matplotlib" and "history" gets me lots
>>>>> of results on our trials and tribulations with version control...
>>>>>
>>>>> Anybody have anything bookmarked?
>>>>>
>>>>> Cheers!
>>>>> Ben Root
>>>>>
>>>>> P.S. - Yes... this is for a book. Stay tuned!
>>>>>
>>>>>
>>>>> ------------------------------------------------------------------------------
>>>>> Infragistics Professional
>>>>> Build stunning WinForms apps today!
>>>>> Reboot your WinForms applications with our WinForms controls.
>>>>> Build a bridge from your legacy apps to the future.
>>>>>
>>>>> http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk
>>>>> _______________________________________________
>>>>> Matplotlib-users mailing list
>>>>> Mat...@li...
>>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Fernando Perez (@fperez_org; http://fperez.org)
>>>> fperez.net-at-gmail: mailing lists only (I ignore this when swamped!)
>>>> fernando.perez-at-berkeley: contact me here for any direct mail
>>>>
>>>
>>
>

For those interested, I have found the release announcement that introduced
the jet colormap: http://ehc.ac/p/matplotlib/mailman/message/188760/ . We
have someone named "Perry" to blame... :-P
Ben Root
On Fri, Aug 1, 2014 at 9:01 PM, Benjamin Root <ben...@ou...> wrote:
> Just to keep my notes in one place... from Matplotlib's "Introduction"
> page is prose that I assume was written by John:
>
> For years, I used to use MATLAB exclusively for data analysis and
> visualization. MATLAB excels at making nice looking plots easy. When I
> began working with EEG data, I found that I needed to write applications to
> interact with my data, and developed and EEG analysis application in
> MATLAB. As the application grew in complexity, interacting with databases,
> http servers, manipulating complex data structures, I began to strain
> against the limitations of MATLAB as a programming language, and decided to
> start over in Python. Python more than makes up for all of MATLAB’s
> deficiencies as a programming language, but I was having difficulty finding
> a 2D plotting package (for 3D VTK <http://www.vtk.org/> more than exceeds
> all of my needs).
>
> When I went searching for a Python plotting package, I had several
> requirements:
>
> - Plots should look great - publication quality. One important
> requirement for me is that the text looks good (antialiased, etc.)
> - Postscript output for inclusion with TeX documents
> - Embeddable in a graphical user interface for application development
> - Code should be easy enough that I can understand it and extend it
> - Making plots should be easy
>
> Finding no package that suited me just right, I did what any
> self-respecting Python programmer would do: rolled up my sleeves and dived
> in. Not having any real experience with computer graphics, I decided to
> emulate MATLAB’s plotting capabilities because that is something MATLAB
> does very well. This had the added advantage that many people have a lot of
> MATLAB experience, and thus they can quickly get up to steam plotting in
> python. From a developer’s perspective, having a fixed user interface (the
> pylab interface) has been very useful, because the guts of the code base
> can be redesigned without affecting user code.
>
>
>
>
>
> On Wed, Jul 30, 2014 at 11:51 PM, Benjamin Root <ben...@ou...> wrote:
>
>> Fernando,
>>
>> This information is going to be the preface of my book on using
>> matplotlib for making an interactive application (sorry, no IPython, the
>> editor wanted to keep the scope tight). So, what I am looking for are some
>> of the major interactive features (who supplied them, and their
>> reasons/purpose). Also, how has interactive matplotlib supported uses "in
>> the wild" such as the Mars Phoenix Lander and recently, the ISEE3 reboot
>> project (that abandoned satellite that was recently revived by citizen
>> scientists).
>>
>> Of, course, any insights to John's original needs/use cases in the early
>> years would be very valuable as well. I could have sworn he has written
>> such missives on the mailing lists, but I can't seem to find them.
>>
>> Cheers!
>> Ben Root
>> On Jul 30, 2014 11:21 PM, "Fernando Perez" <fpe...@gm...> wrote:
>>
>>> Hi Ben,
>>>
>>> if by interactive plotting you refer to using it interactively via
>>> ipython and other such systems, there's a good part of that history that is
>>> spread somewhere between the early mpl and ipython archives AND John's and
>>> my personal inboxes.
>>>
>>> A good chunk of that (not all, mind you, since many others contributed)
>>> happened with John and I working on it, and sadly he's not with us and I
>>> had a loss of my early email (anything older than 2005) when I left the
>>> University of Colorado.
>>>
>>> I'd be happy to answer some questions if you have them, to the best of
>>> my memory. Probably quicker over skype/phone, ping me directly (at my
>>> Berkeley address) if you want.
>>>
>>> Cheers
>>>
>>> f
>>>
>>>
>>>
>>> On Wed, Jul 30, 2014 at 7:20 PM, Benjamin Root <ben...@ou...> wrote:
>>>
>>>> Hello all,
>>>>
>>>> I am trying to put together notes for a writeup on a short history of
>>>> matplotlib (in particular, its uses for interactive plotting). I have John
>>>> Hunter's SciPy 2012 Keynote, which helps, but I was hoping for some other
>>>> sources.
>>>>
>>>> Unfortunately, searching for "matplotlib" and "history" gets me lots of
>>>> results on our trials and tribulations with version control...
>>>>
>>>> Anybody have anything bookmarked?
>>>>
>>>> Cheers!
>>>> Ben Root
>>>>
>>>> P.S. - Yes... this is for a book. Stay tuned!
>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> Infragistics Professional
>>>> Build stunning WinForms apps today!
>>>> Reboot your WinForms applications with our WinForms controls.
>>>> Build a bridge from your legacy apps to the future.
>>>>
>>>> http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk
>>>> _______________________________________________
>>>> Matplotlib-users mailing list
>>>> Mat...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>>>
>>>>
>>>
>>>
>>> --
>>> Fernando Perez (@fperez_org; http://fperez.org)
>>> fperez.net-at-gmail: mailing lists only (I ignore this when swamped!)
>>> fernando.perez-at-berkeley: contact me here for any direct mail
>>>
>>
>

Hi,
I am using the standard matplotlib on Ubuntu 14.04.
I was creating a custom colormap using the standard dict with
rgb values method (something I have done before as well). However,
one of the values in the 'r' array was 55 instead of .55 and contourf
would die saying 'invalid rgb value' which was somewhere near 51.
Ideally, matplotlib should catch this, and I did some digging to see what
is happening. I finally saw this bit of code in 473 in colors.py (in the
function
makMappingArray)
np.clip(lut, 0.0, 1.0)
it appears that np.clip does not modify its arguments and this should
instead
be
lut = np.clip(lut, 0.0, 1.0)
which fixed the problem. Of course, if this error(?) was not there, I would
have
never found the problem in my custom colormap, so not all bad afer all ;)
Thanks,
Joy
-- 
The best ruler, when he finishes his
tasks and completes his affairs,
the people say
"It all happened naturally"
 - Te Tao Ch'ing

Just to keep my notes in one place... from Matplotlib's "Introduction" page
is prose that I assume was written by John:
For years, I used to use MATLAB exclusively for data analysis and
visualization. MATLAB excels at making nice looking plots easy. When I
began working with EEG data, I found that I needed to write applications to
interact with my data, and developed and EEG analysis application in
MATLAB. As the application grew in complexity, interacting with databases,
http servers, manipulating complex data structures, I began to strain
against the limitations of MATLAB as a programming language, and decided to
start over in Python. Python more than makes up for all of MATLAB’s
deficiencies as a programming language, but I was having difficulty finding
a 2D plotting package (for 3D VTK <http://www.vtk.org/> more than exceeds
all of my needs).
When I went searching for a Python plotting package, I had several
requirements:
 - Plots should look great - publication quality. One important
 requirement for me is that the text looks good (antialiased, etc.)
 - Postscript output for inclusion with TeX documents
 - Embeddable in a graphical user interface for application development
 - Code should be easy enough that I can understand it and extend it
 - Making plots should be easy
Finding no package that suited me just right, I did what any
self-respecting Python programmer would do: rolled up my sleeves and dived
in. Not having any real experience with computer graphics, I decided to
emulate MATLAB’s plotting capabilities because that is something MATLAB
does very well. This had the added advantage that many people have a lot of
MATLAB experience, and thus they can quickly get up to steam plotting in
python. From a developer’s perspective, having a fixed user interface (the
pylab interface) has been very useful, because the guts of the code base
can be redesigned without affecting user code.
On Wed, Jul 30, 2014 at 11:51 PM, Benjamin Root <ben...@ou...> wrote:
> Fernando,
>
> This information is going to be the preface of my book on using matplotlib
> for making an interactive application (sorry, no IPython, the editor wanted
> to keep the scope tight). So, what I am looking for are some of the major
> interactive features (who supplied them, and their reasons/purpose). Also,
> how has interactive matplotlib supported uses "in the wild" such as the
> Mars Phoenix Lander and recently, the ISEE3 reboot project (that abandoned
> satellite that was recently revived by citizen scientists).
>
> Of, course, any insights to John's original needs/use cases in the early
> years would be very valuable as well. I could have sworn he has written
> such missives on the mailing lists, but I can't seem to find them.
>
> Cheers!
> Ben Root
> On Jul 30, 2014 11:21 PM, "Fernando Perez" <fpe...@gm...> wrote:
>
>> Hi Ben,
>>
>> if by interactive plotting you refer to using it interactively via
>> ipython and other such systems, there's a good part of that history that is
>> spread somewhere between the early mpl and ipython archives AND John's and
>> my personal inboxes.
>>
>> A good chunk of that (not all, mind you, since many others contributed)
>> happened with John and I working on it, and sadly he's not with us and I
>> had a loss of my early email (anything older than 2005) when I left the
>> University of Colorado.
>>
>> I'd be happy to answer some questions if you have them, to the best of my
>> memory. Probably quicker over skype/phone, ping me directly (at my Berkeley
>> address) if you want.
>>
>> Cheers
>>
>> f
>>
>>
>>
>> On Wed, Jul 30, 2014 at 7:20 PM, Benjamin Root <ben...@ou...> wrote:
>>
>>> Hello all,
>>>
>>> I am trying to put together notes for a writeup on a short history of
>>> matplotlib (in particular, its uses for interactive plotting). I have John
>>> Hunter's SciPy 2012 Keynote, which helps, but I was hoping for some other
>>> sources.
>>>
>>> Unfortunately, searching for "matplotlib" and "history" gets me lots of
>>> results on our trials and tribulations with version control...
>>>
>>> Anybody have anything bookmarked?
>>>
>>> Cheers!
>>> Ben Root
>>>
>>> P.S. - Yes... this is for a book. Stay tuned!
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Infragistics Professional
>>> Build stunning WinForms apps today!
>>> Reboot your WinForms applications with our WinForms controls.
>>> Build a bridge from your legacy apps to the future.
>>>
>>> http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk
>>> _______________________________________________
>>> Matplotlib-users mailing list
>>> Mat...@li...
>>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>>>
>>>
>>
>>
>> --
>> Fernando Perez (@fperez_org; http://fperez.org)
>> fperez.net-at-gmail: mailing lists only (I ignore this when swamped!)
>> fernando.perez-at-berkeley: contact me here for any direct mail
>>
>