matplotlib-users Mailing List for matplotlib (Page 7)

On Wed, Feb 16, 2011 at 9:16 AM, Stephan Markus <zw...@we...> wrote:
>
> Hi,
>
> I am trying to display some complex values in a polar plot. Displaying
> linear magnitude vs. angle - of course - works without any issues. But I'd
> rather display the logarithmic magnitute vs. angle. Since the data for the
> radius gets negative then, it'll be wrapped around / rotated by 180deg by
> matplotlib.
>
> How can I display negative values for the radius w/o having them rotated by
> 180deg?
>
> Of course I can add an offset to the data before plotting it but since my
> plot is interactive and I use the xdata/ydata of events I'd like them to
> represent the real data, without an offset. I thought it might be possible
> to achieve with a custom transformation but I don't actually get it to
> work.
>
> -Stephan
> --
> View this message in context:
> http://old.nabble.com/Polar-plot---problem-with-negative-values-for-radius-tp30936638p30936638.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
>
>
Stephan,
>From the polar axes object, you can call ax.set_rscale('log') and that will
automatically make the radial ticks scale and label the axes properly. You
can then input the original data as you would without worry of negative
values.
Let us know how that works for you!
Ben Root

Hi,
I've written two plot scripts for plotting functions f: R -> C.
(Scalar mappings of a real to a complex domain.)
The function plotcf(...) plots the modulus
as y value and the phase as color code.
The function stemcf(...) does the same, but
emulates a stem plot.
I attached also two demo scripts that show these
functions in action.
If you have any questions or improvements,
please tell me.
Feel free to add these scripts to the gallery
if you think they could be of a broader
interest.
-- Raoul

Hi,
I am trying to display some complex values in a polar plot. Displaying
linear magnitude vs. angle - of course - works without any issues. But I'd
rather display the logarithmic magnitute vs. angle. Since the data for the
radius gets negative then, it'll be wrapped around / rotated by 180deg by
matplotlib.
How can I display negative values for the radius w/o having them rotated by
180deg?
Of course I can add an offset to the data before plotting it but since my
plot is interactive and I use the xdata/ydata of events I'd like them to
represent the real data, without an offset. I thought it might be possible
to achieve with a custom transformation but I don't actually get it to work.
-Stephan
-- 
View this message in context: http://old.nabble.com/Polar-plot---problem-with-negative-values-for-radius-tp30936638p30936638.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

> Ben, John: Later this week or next, I'll take a crack at adding both of these 
to quiver.py and 
> axes.py (one under the name "streamlines", the other as "streamplot"). 
This is a great idea. I've had some time to improve the code, and so you have 
something better to work with! If you have any questions or need the code 
modifying, I'm happy to help - should have free time at the weekend and next 
week. I've also added density in both directions (nice idea - hadn't thought 
about this) and variable color as well as width.
The new code is at http://www.atm.damtp.cam.ac.uk/people/tjf37/streamplot.py and 
there are new sample plots at 
http://www.atm.damtp.cam.ac.uk/people/tjf37/streamlines1.png and 
http://www.atm.damtp.cam.ac.uk/people/tjf37/streamlines2.png .
> You probably want to use a compound path (one object for the entire
> plot). See the tutorial 
athttp://matplotlib.sourceforge.net/users/path_tutorial.html, in
> particular the compound path for the histogram example near the end,
> and let me know if you have any questions.
John, thanks for the hints. In the end I used a LineCollection for each 
streamline because I didn't see how to set different properties (colour and 
width) for different portions of the line in the compound path. LineCollection 
performs well enough for this plot so I'm happy with this solution.
Tom

heya,
Is there an easy way to colour-code a Matplotlib histogram with a single set
of data?
So for example, you'd have a bell-shaped histogram, and the middle 50% might
be green, the regions 20% to the left and right of that might be yellow, and
the 5% either side beyond that could be red.
I couldn't seem to find anything in the Matplotlib options for this - any
suggestions?
Cheers,
Victor

On Tue, Feb 15, 2011 at 6:29 PM, Paul Leopardi
<pau...@ii...>wrote:
> Hi Benjamin,
> On 2011年2月16日 03:07:25 AM you wrote:
> > I have not figured out what is causing the difference between my
> computers.
> > This might be backend-dependent (and maybe version-dependent). Have you
> > tested your code on different backends?
>
> I don't know what you mean by different backends. What are the possible
> ones,
> and how do you configure them? Where is this documented?
> Best, Paul
>
http://matplotlib.sourceforge.net/faq/installing_faq.html#what-is-a-backend
Personally, I use the second approach with "matplotlib.use('GTKAgg')" or
whatnot. Based on what I saw you listed as available packages, you should
have TkAgg and WxAgg available.
Ben Root

Hi all,
I'm using a matplotlib.widgets.Slider on my animated figure. Sometime, I
want to refresh the maximum value of the slider (since new values to plot
were generated).
Is it possible to update the "valmax" value of the slider? If not, is it
possible to delete the slider and create a new one?
Thanx!

wukan, on 2011年02月14日 23:39, wrote:
> Hi ,When I use matplotlib to draw 2D graphics in django web site,I encounter
> a problem.
> when server users use matplotlib to draw graphics simultaneously will
> cause website collapse.
> when one user use matplotlib to draw graphics will have no problem.
Is there an error / stack trace generated? Can you give an
example of how you are using matplotlib from django? 
I can imagine there being some issue if you are using the pyplot
interface to deal with all user requests (e.g. plt.plot, instead
of allocating an axes object for each user and calling ax.plot). 
There's no way for us to know unless you provide more details.
> i suppose matplotlib doesnot support multithreading drawing.
> so i put the draw function in a thread . it can't work as before.
I don't follow.
 
> so why matplotlib doesnot support multithreading drawing?
> How to solve this problem.
Depending on the load, the nature of desired plots, and the need
for user intervention, you might be able to get around the issues
you're having just by spawning a new process to do the plotting.
P.S. 
I try to answer all of the questions I feel capable of answering
on the mailing list, there is no need to send duplicates of
mailing list questions directly to me.
best,
-- 
Paul Ivanov
314 address only used for lists, off-list direct email at:
http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7 

Bala subramanian, on 2011年02月15日 16:06, wrote:
> Friends,
> I created a histogram plot using data files that have discrete values
> (sample file attached 'test.dat').However when i view the plot, i see that
> the bars are not located exactly over the values. For example in the
> attached figure (test.png), i see a bar (gray) placed between values 1 and
> 2, while there is no such value between 1 and 2. Precisely i would like to
> know how to make histogram for discrete data values.
Hi Bala,
Hist by default will make 10 bins with the same width, so
depending on the distribution of your data, it will shift the
locations of the bins (which is the effect you are seeing). 
What you'll want to do is pass the 'bins' keyword to ax.hist to
avoid this. From the docstring
 
*bins*:
 Either an integer number of bins or a sequence giving the
 bins. If *bins* is an integer, *bins* + 1 bin edges
 will be returned, consistent with :func:`numpy.histogram`
 for numpy version >= 1.3, and with the *new* = True argument
 in earlier versions. Unequally spaced bins are supported if
 *bins* is a sequence.
Here's an example:
In [8]: a = np.random.randint(20,size=(20))
In [9]: ax = plt.gca()
In [10]: ax.hist(a,bins=np.arange(a.min(),a.max()+2,1)-.5)
Out[10]: 
(array([1, 3, 1, 1, 0, 3, 1, 0, 0, 0, 0, 2, 1, 0, 1, 1, 0, 0, 2,
3]),
 array([ -0.5, 0.5, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5,
7.5,
 8.5, 9.5, 10.5, 11.5, 12.5, 13.5, 14.5, 15.5,
16.5,
 17.5, 18.5, 19.5]),
 <a list of 20 Patch objects>)
In [11]: ax.hist(a) # the default bins=10
(array([4, 2, 3, 1, 0, 2, 1, 2, 0, 5]),
 array([ 0. , 1.9, 3.8, 5.7, 7.6, 9.5, 11.4, 13.3,
15.2,
 17.1, 19. ]),
 <a list of 10 Patch objects>)
best,
-- 
Paul Ivanov
314 address only used for lists, off-list direct email at:
http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7 

On Tue, Feb 8, 2011 at 8:43 PM, Benjamin Root <ben...@ou...> wrote:
> On Tue, Feb 8, 2011 at 5:53 PM, Paul Leopardi <pau...@ii...>wrote:
>
>> Hi Ben,
>> On Wed, 9 Feb 2011 03:15:19 AM you wrote:
>> > As formatted, the code would not run. I presume that everything after
>> "for
>> > j in range(0,M):" should be indented? When I did that and ran it in
>> > ipython, I could not reproduce your problem. What version of matplotlib
>> > are you running?
>>
>> Thanks for your continued close attention to this undoubted problem.
>>
>> Your email system mangled the indentation. The correct indentation is
>> displayed at
>> http://sourceforge.net/mailarchive/message.php?msg_id=27020771
>>
>> I have also included a copy of the script matplotlib_bug_example.py with
>> this
>> message. [*Not* posted to the list.] Here is how I run it:
>>
>> ipython -pylab
>> Python 2.6.2 (r262:71600, Oct 28 2010, 20:54:41)
>> Type "copyright", "credits" or "license" for more information.
>>
>> IPython 0.10 -- An enhanced Interactive Python.
>> ? -> Introduction and overview of IPython's features.
>> %quickref -> Quick reference.
>> help -> Python's own help system.
>> object? -> Details about 'object'. ?object also works, ?? prints more.
>>
>> Welcome to pylab, a matplotlib-based Python environment.
>> For more information, type 'help(pylab)'.
>>
>> In [1]: run matplotlib_bug_example.py
>>
>> My original post
>> http://sourceforge.net/mailarchive/message.php?msg_id=27016368
>> listed what I thought were the relevant versions:
>>
>> Quote
>> I am using openSUSE 11.2 with
>> python-base-2.6.2-6.7.1.x86_64
>> python-matplotlib-1.0.1-20.1.x86_64
>> python-matplotlib-tk-1.0.1-20.1.x86_64
>> python-matplotlib-wx-1.0.1-20.1.x86_64
>> Unquote
>>
>> I have since run the script on a second machine which uses Ubuntu Karmic,
>> with
>> identical results.
>>
>> Versions in brief:
>> Linux linfinit 2.6.31.12-0.1-default #1 SMP PREEMPT 2010年12月10日 11:18:32
>> +0100
>> x86_64 x86_64 x86_64 GNU/Linux
>>
>> IPython-0.10-3.2.noarch
>> python-2.6.2-6.7.1.x86_64
>> python-matplotlib-1.0.1-20.1.x86_64
>> python-matplotlib-tk-1.0.1-20.1.x86_64
>> python-matplotlib-wx-1.0.1-20.1.x86_64
>> python-numpy-1.5.0-17.2.x86_64
>> python-tk-2.6.2-6.7.1.x86_64
>>
>> Linux cheeze 2.6.31-22-generic #70-Ubuntu SMP Wed Dec 1 23:51:13 UTC 2010
>> i686 GNU/Linux
>>
>> ipython 0.10-1
>> python 2.6.4-0ubuntu1
>> python-matplotlib 0.99.0-1ubuntu1
>> python-numpy 1:1.3.0-3
>> python-tk 2.6.3-0ubuntu1
>>
>>
>> I have included a listing showing all versions of all packages with names
>> containing the string "python", on both machines. [*Not* posted to the
>> list.]
>> Best, Paul
>>
>>
> Trying out the script on another machine of mine, I was able to reproduce
> the problem. I will have to see what is the difference between my two
> computers that would cause the other one to work perfectly fine.
>
> Ben Root
>
>
Paul,
I have not figured out what is causing the difference between my computers.
This might be backend-dependent (and maybe version-dependent). Have you
tested your code on different backends?
Ben Root

On Tue, Feb 15, 2011 at 9:24 AM, Sebastian Busch <web...@th...> wrote:
> Dear list,
>
> if I do a
>
> plot([1,2],[1,2])
> plot([1,2],[1,3])
> plot([1,2],[1,4])
>
> I will get three lines. All have linestyle='-', the colour is changed
> automatically: blue, green, red, ...
>
> Can I change this behaviour to: All have the colour black, and the
> linestyle is changed /automatically/ '-', '--', '-.', ...?
You can use itertools.cycle, that will repeatedly loop over a sequence of items:
import matplotlib.pyplot as pl
from itertools import cycle
styles = cycle(['k-', 'k--', 'k-.'])
plot([1,2], [1,2], styles.next())
plot([1,2], [1,3], styles.next())
plot([1,2], [1,4], styles.next())
Ryan
-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

2011年2月14日 Gaël KANEKO <kan...@ho...>
> Hi,
> I have some problems to plot a 3d plot_surface (and contour plot) in log
> scale (y and z or x,y and z).
> There is nothink in the help sections of thus plot to plot them in log
> scale (neither in thus plot code commentary).
> I tried to find a solution by myself (many try as "log=True",
> "xscale='log'", "scale='log'", or "set_xscale('log')"...) but it doesn't
> work.
> I tried to use "LogFormatter" (ticker) but i failed (maybe I am doing
> something wrong (I am a newbe) but i tried many things).
> I try to found a solution on forums and this mailing list and what i found
> nearest of my problem is this topic:
>
> http://stackoverflow.com/questions/3909794/plotting-mplot3d-axes3d-xyz-surface-plot-with-log-scale
> ‏ They said this problem had no solution. Is it true? have somebody solved
> this problem?
>
> An other solution is to plot log(Data) and change ticks with "set_ticks"
> (for exemple) but it seems to only work with 2D plot. I tried too :(
>
> To be unterstanding easier, this is an exemple of the code to plot in log
> scale:
> import matplotlib.pyplot as plt# (i am under '1.0.0')
> import numpy as np
>
> #Data
> x = np.logspace(0, 4, 10)
> y = np.logspace(0, 4, 10)
> Z = np.arange(100).reshape((10,10))
>
> #Min and Max for x,y and Z
> minx=np.min(x)
> maxx=np.max(x)
> miny=np.min(y)
> maxy=np.max(y)
> minz=np.min(Z)
> maxz=np.max(Z)
>
> #figure
> fig = plt.figure()
> ax = fig.gca(projection='3d')
>
>
> ax.plot_surface(X, Y, Z, rstride=8, cstride=8, alpha=0.3)
> cset = ax.contour(X, Y, Z, zdir='z', offset=minz)
> cset = ax.contour(X, Y, Z, zdir='x', offset=minx)
> cset = ax.contour(X, Y, Z, zdir='y', offset=miny)
>
> ax.set_xlabel("X")
> ax.set_xlim3d(minx,maxx)
> ax.set_ylabel("Y")
> ax.set_ylim3d(miny,maxy)
> ax.set_zlabel("Z")
> ax.set_zlim3d(minz,maxz)
> fig.savefig("plot00.png")
>
>
>
> Has someone got a solution?
> Thanks!
> Regards,
> Gaël
>
>
I can confirm (with a modified version of your script) that mplot3d does not
properly handle non-linear scaling. While it is possible to set the axis
scale through a command like:
ax.w_xaxis.set_scale('log')
but the placement of the tickers are wrong and it fails because mplot3d does
some weird stuff with the ticker formatter rather than just letting the
formatter do its job.
I will look into this further to see if I can fix this.
Ben Root

Dear list,
if I do a
plot([1,2],[1,2])
plot([1,2],[1,3])
plot([1,2],[1,4])
I will get three lines. All have linestyle='-', the colour is changed
automatically: blue, green, red, ...
Can I change this behaviour to: All have the colour black, and the
linestyle is changed /automatically/ '-', '--', '-.', ...?
Thanks in advance,
Sebastian.

On 2/14/11 4:54 PM, Benjamin Root wrote:
> On Mon, Feb 14, 2011 at 5:30 PM, John Hunter <jd...@gm... 
> <mailto:jd...@gm...>> wrote:
>
> On Sun, Feb 13, 2011 at 11:45 PM, Tom Flannaghan <tj...@ca...
> <mailto:tj...@ca...>> wrote:
>
> > It would also be helpful if anyone has suggestions on a
> particular issue I had.
> > Currently, to plot variable-width lines (i.e. streamlines2.png)
> I use a plot
> > command for each line segment which is very slow and nasty. Is
> there a better
> > way I'm missing?
>
> You probably want to use a compound path (one object for the entire
> plot). See the tutorial at
> http://matplotlib.sourceforge.net/users/path_tutorial.html, in
> particular the compound path for the histogram example near the end,
> and let me know if you have any questions.
>
> JDH
>
>
> Personally, I am more a fan of Ray's version, although Tom's version 
> would integrate more nicely with the current mpl codebase. There are 
> some nice features with Ray's version such as allowing to choose 
> density in both x and y directions.
>
> I guess the major question is which style do we like better? Maybe we 
> could use both of these code bases to come up with a nice, generalized 
> version?
>
> Ben Root
>
Ben, John: Later this week or next, I'll take a crack at adding both of 
these to quiver.py and axes.py (one under the name "streamlines", the 
other as "streamplot").
-Jeff
-- 
Jeffrey S. Whitaker Phone : (303)497-6313
Meteorologist FAX : (303)497-6449
NOAA/OAR/PSD R/PSD1 Email : Jef...@no...
325 Broadway Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg

Hi Aman,
Thanks a lot for your help and providing me the link to the function. It
sorted out my query :)
Cheers
Omer
On Tue, Feb 15, 2011 at 14:44, Aman Thakral <ama...@gm...> wrote:
> Hi Omer,
>
> use the subplots_adjust keyword argument (or click on the adjust
> subplots icon in the navigation toolbar at the bottom of the figure).
>
>
> http://matplotlib.sourceforge.net/api/figure_api.html#matplotlib.figure.Figure.subplots_adjust
>
> -Aman
>
> On Tue, Feb 15, 2011 at 6:05 AM, Omer Khalid <okh...@gm...>
> wrote:
> > Hi,
> > I am trying to create two subplots in the same figure. Currently, the
> x-axis
> > of first plot overlaps with the title of second plot.
> > I was wondering if there is a function for figure object that allows to
> > create vertical space between two plots so that the axis and title text
> > doesn't overlap?
> > Regards
> > omer
> >
> ------------------------------------------------------------------------------
> > The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE:
> > Pinpoint memory and threading errors before they happen.
> > Find and fix more than 250 security defects in the development cycle.
> > Locate bottlenecks in serial and parallel code that limit performance.
> > http://p.sf.net/sfu/intel-dev2devfeb
> > _______________________________________________
> > Matplotlib-users mailing list
> > Mat...@li...
> > https://lists.sourceforge.net/lists/listinfo/matplotlib-users
> >
> >
>

Hi Omer,
use the subplots_adjust keyword argument (or click on the adjust
subplots icon in the navigation toolbar at the bottom of the figure).
http://matplotlib.sourceforge.net/api/figure_api.html#matplotlib.figure.Figure.subplots_adjust
-Aman
On Tue, Feb 15, 2011 at 6:05 AM, Omer Khalid <okh...@gm...> wrote:
> Hi,
> I am trying to create two subplots in the same figure. Currently, the x-axis
> of first plot overlaps with the title of second plot.
> I was wondering if there is a function for figure object that allows to
> create vertical space between two plots so that the axis and title text
> doesn't overlap?
> Regards
> omer
> ------------------------------------------------------------------------------
> The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE:
> Pinpoint memory and threading errors before they happen.
> Find and fix more than 250 security defects in the development cycle.
> Locate bottlenecks in serial and parallel code that limit performance.
> http://p.sf.net/sfu/intel-dev2devfeb
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
>

Hi,
I am trying to create two subplots in the same figure. Currently, the x-axis
of first plot overlaps with the title of second plot.
I was wondering if there is a function for figure object that allows to
create vertical space between two plots so that the axis and title text
doesn't overlap?
Regards
omer

Hi everyone,
I'm not quite sure what to call my problem so searching for it is 
difficult, but I'll try and describe it the best I can:
Matplotlib in python on OSX seems to have an issue with the pan/zoom 
tool. When I click it and drag the plot around, it does not update 
until I release the mouse. I've used this function on other *nix 
machines and it seems to be fine. Here's a quick video describing what 
I mean if my description is unclear: 
http://www.youtube.com/watch?v=_cqUGpHGrl0
I have tried to switch the backend to osx in the matplotlibrc file, but 
the result is the same. Any help you can provide would be greatly 
appreciated. Thanks!
-Robert

jules hummon, on 2011年02月14日 07:23, wrote:
> Feel free to 'save and run', pass along, or ignore.
> This was my valentine's day present today.
Thank you for sharing! I took the liberty of livening it up for
my sweetheart.
#---------------------------------------------------
# hohumheartbeat.py - a more lively hohumheart.py ;)
import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
from matplotlib.patches import Polygon
# force square figure and square axes looks better for polar, IMO
width, height = mpl.rcParams['figure.figsize']
size = min(width, height)
# make a square figure
fig = plt.figure(figsize=(size, size))
ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], polar=True, axisbg='#ffffff')
ax2 = fig.add_axes([0.45, .9, 0.1, 0.1], polar=True, axisbg='#ffffff')
ax.set_rmax(2.0)
ax2.set_rmax(4.0)
ax2.spines['polar'].set_visible(False)
ax2.patch.set_alpha(.3)
for a in ax,ax2:
 a.set_xticks([])
 a.set_yticks([])
 ax.grid(False)
theta = np.linspace(0,1,100)*np.pi*2
r = 1*(1-np.cos(theta))
ncards = 5
step = 2*np.pi/ncards
pdict = dict(fc='r',ec='k', alpha=.5)
for ii in range(ncards):
 tr = np.column_stack((theta+ii*step, r))
 ax.add_patch(Polygon(tr, **pdict))
# from WolframMath "Heart Curve"
r2 = 2 - 2*np.sin(theta)
r2 += np.sin(theta) * np.sqrt(np.abs(np.cos(theta))) / (np.sin(theta)+1.4)
tr2 = np.column_stack((theta, r2))
ax2.add_patch(Polygon(tr2,**pdict)) # heart
kwargs = dict(transform=ax2.transAxes, va='center', fontsize=20)
ax2.text(0,.45,"I",ha='right',**kwargs)
ax2.text(1,.4,"you",ha='left',**kwargs)
beat = np.tan(np.linspace(0, np.pi*2, 100))
beat[0:20] = beat[60:80]
beat[-20:] = beat[20:40]
beat -= beat.min()
beat /= beat.max()
i=0; beatlen = len(beat)-1;
def heartbeat(e):
 global i;
 i = (i+1) % (beatlen)
 y = beat[i]
 ax2.set_rmax(y*4. + 4.)
 ax2.draw(ax.figure.canvas.get_renderer())
 ax2.figure.canvas.blit(ax2.bbox)
 #plt.draw() #use if the last two lines cause trouble
# even your mouse movements make my heart skip a bit!
cid = ax.figure.canvas.mpl_connect('idle_event', heartbeat)
print "ax.figure.canvas.mpl_disconnect(%d)" %cid
print "#run the line above to 'flatline' (stop heartbeat)"
plt.show()
best,
-- 
Paul Ivanov
314 address only used for lists, off-list direct email at:
http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7 

On Mon, Feb 14, 2011 at 5:30 PM, John Hunter <jd...@gm...> wrote:
> On Sun, Feb 13, 2011 at 11:45 PM, Tom Flannaghan <tj...@ca...> wrote:
>
> > It would also be helpful if anyone has suggestions on a particular issue
> I had.
> > Currently, to plot variable-width lines (i.e. streamlines2.png) I use a
> plot
> > command for each line segment which is very slow and nasty. Is there a
> better
> > way I'm missing?
>
> You probably want to use a compound path (one object for the entire
> plot). See the tutorial at
> http://matplotlib.sourceforge.net/users/path_tutorial.html, in
> particular the compound path for the histogram example near the end,
> and let me know if you have any questions.
>
> JDH
>
>
Personally, I am more a fan of Ray's version, although Tom's version would
integrate more nicely with the current mpl codebase. There are some nice
features with Ray's version such as allowing to choose density in both x and
y directions.
I guess the major question is which style do we like better? Maybe we could
use both of these code bases to come up with a nice, generalized version?
Ben Root

On Sun, Feb 13, 2011 at 11:45 PM, Tom Flannaghan <tj...@ca...> wrote:
> It would also be helpful if anyone has suggestions on a particular issue I had.
> Currently, to plot variable-width lines (i.e. streamlines2.png) I use a plot
> command for each line segment which is very slow and nasty. Is there a better
> way I'm missing?
You probably want to use a compound path (one object for the entire
plot). See the tutorial at
http://matplotlib.sourceforge.net/users/path_tutorial.html, in
particular the compound path for the histogram example near the end,
and let me know if you have any questions.
JDH

On 2/13/11 10:45 PM, Tom Flannaghan wrote:
> Hi,
>
> I've written a script to roughly emulate the elegant streamline plots found in
> Mathematica. The code is available at
> http://www.atm.damtp.cam.ac.uk/people/tjf37/streamplot.py and example plots at
> http://www.atm.damtp.cam.ac.uk/people/tjf37/streamlines1.png and
> streamlines2.png. It's a pretty hacky script, but fast and fairly robust. If
> anyone finds this script useful and has comments/suggestions, I'm happy to do a
> bit more work.
>
> It would also be helpful if anyone has suggestions on a particular issue I had.
> Currently, to plot variable-width lines (i.e. streamlines2.png) I use a plot
> command for each line segment which is very slow and nasty. Is there a better
> way I'm missing?
>
> Tom
Tom: This is really nice! I'd like to see some version of your code 
incorporated into matplotlib. Regarding your question about 
variable-width lines, I don't know of any way to do that - but perhaps 
someone with more detailed knowledge of matplotlib internals will comment.
-Jeff
-- 
Jeffrey S. Whitaker Phone : (303)497-6313
Meteorologist FAX : (303)497-6449
NOAA/OAR/PSD R/PSD1 Email : Jef...@no...
325 Broadway Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg

Thank you for your help. I upgraded to the latest development version, 
and as you said, memory use dropped a ton. I will have to test more to 
confirm that the problem is completely gone, but this appears to bring 
memory usage down to something quite manageable (at least on my 8gb box 
...).
Tom
On 02/09/2011 07:30 PM, Robert Abiad wrote:
> Tom,
>
> I just went through this, though with version 1.01 of mpl, so it may be different. You can read the
> very long thread at:
>
> http://www.mail-archive.com/mat...@li.../msg20031.html
>
> Those who maintain mpl don't think there is a memory leak. What I found was that imshow() does
> consume a lot of memory (now fixed in the development version) and that the first 2 or so uses build
> on each other, but after that it levels off giving back memory after close(). There is a
> discrepancy between what python reports it's using and what the OS reports (I had 500MB from the OS,
> but only 150MB from python). There is a chance that ipython is caching your results (try ipython
> -pylab -cs 0), but when I ran without ipython, python still had a large portion of memory.
>
> -robert
>
> On 2/9/2011 3:52 PM, Tom Dimiduk wrote:
>> I am using matplotlib pylab in association with ipython -pylab to show
>> many large (~2000x2000 or larger) images. Each time I show another
>> image it consumes more memory until eventually exhausting all system
>> memory and making my whole system unresponsive.
>>
>> The easiest way to replicate this behaviour is with
>> a = ones((3333,3333))
>> imshow(a)
>>
>> optionally
>>
>> close()
>>
>> and then
>>
>> imshow(a)
>>
>> again. I am using ipython .10.1 and matplotlib 0.99.3. Is there
>> something I should be doing differently to avoid this problem? Is it
>> fixed in a later version?
>>
>> Thanks,
>> Tom
>>
>> ------------------------------------------------------------------------------
>> The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE:
>> Pinpoint memory and threading errors before they happen.
>> Find and fix more than 250 security defects in the development cycle.
>> Locate bottlenecks in serial and parallel code that limit performance.
>> http://p.sf.net/sfu/intel-dev2devfeb
>> _______________________________________________
>> Matplotlib-users mailing list
>> Mat...@li...
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
> ------------------------------------------------------------------------------
> The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE:
> Pinpoint memory and threading errors before they happen.
> Find and fix more than 250 security defects in the development cycle.
> Locate bottlenecks in serial and parallel code that limit performance.
> http://p.sf.net/sfu/intel-dev2devfeb
> _______________________________________________
> Matplotlib-users mailing list
> Mat...@li...
> https://lists.sourceforge.net/lists/listinfo/matplotlib-users

Aman Thakral, on 2011年02月09日 15:40, wrote:
> Hi,
> 
> I was just wondering, how would I go about redrawing only a single element
> (i.e. an artist)? I know that matplotlib.artist.Artist has a draw() method
> that accepts a renderer as the argument.
> 
> I tried something along the lines of:
> 
> renderer = fig.canvas.get_renderer()
> title = ax.set_title("This is my title")
> title.draw(renderer)
> 
> But have not had any luck. I'm not sure what I'm missing. Any help would
> be greatly appreciated.
Hi Aman,
To see the affects of rendering something new, you can use:
 ax.figure.canvas.blit(ax.title.get_bbox_patch())
If you intend to change the title several times, however, the
above will just keep over-plotting on top of the previous titles.
In that case, you'll want to use the animated=True keyword and
canvas.restore_region along with the blitting -- see the
animation examples for how to do that.
best,
-- 
Paul Ivanov
314 address only used for lists, off-list direct email at:
http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7 

Bartosz Telenczuk, on 2011年02月13日 23:16, wrote:
> Hi,
> 
> I am writting an application in which I update dynamically the state 
> of the figures. When I am done I call the Figure.canvas.draw function 
> to redraw the figure. However, when the window was previously closed 
> by the user the update can be skipped.
> 
> Is there a way to tell from a figure handle if the figure is shown on 
> screen or not?
> 
> Currently, I solve this problem with a callback which sets the figure 
> handle to None on figure close event. However, I guess there might be 
> a more direct way of doing that. What would you suggest?
> 
> Thanks a lot for your help.
Hi Bartosz,
I don't think there's currently a backend independent way of
doing it outside of the approach you have taken. 
Having a quick look using f = plt.gcf() before and after closing
the figure, with a WX backend, the f.canvas object changes
to an instance of <class 'wx._core._wxPyDeadObject'>, and loses
all of its usual methods. For GTK - looks like f.canvas.window
gets set to None. 
So if you're only targeting one backend, there might be some
simple way like this to find out if a figure is being shown using
from the figure handle.
best,
-- 
Paul Ivanov
314 address only used for lists, off-list direct email at:
http://pirsquared.org | GPG/PGP key id: 0x0F3E28F7