matplotlib-users Mailing List for matplotlib

Thanks, that was helpful.
On Sunday 16 May 2010 02:23:02 pm Eric Firing wrote:
> On 05/16/2010 10:19 AM, Philipp K. Janert wrote:
> > Let's say I am running an interactive session
> > (ipython -pylab), and now issue the following
> > commands:
> >
> > 	x = linspace(0, 10, 100 )
> > 	plot( x, sin(x) )
> > 	ylim( -2, 2 )
> > 	plot( x, cos(x) )
> >
> > Then the second plot command seems to reset
> > the plot limits to [-1,1] - which makes sense for
> > the figure, but is not what I requested.
> >
> > Is this behavior intended? It seems odd to me,
> > since generally matplotlib seems to retain state
> > that has between invocations of plot().
>
> Good question. The control of autoscaling has a somewhat clunky
> interface via Axes methods, and via the plot function. Your two options
> are to follow the ylim call with the ugly
>
> gca().set_autoscaley_on(False)
>
> or to add a kwarg to all subsequent plot calls:
>
> plot(x, cos(x), scaley=False)
>
> A possible mpl improvement would be to add a kwarg to the pyplot.ylim
> and xlim functions, e.g.
>
> ylim(-2, 2, keep=True)
>
> Calling the kwarg "hold" would read better to my eye, but would conflict
> with the use of "hold" to mean "keep all prior plot elements". Maybe
> there is a better name, e.g. setting "auto=False" to mean "don't
> autoscale this on the next plot command". Or "save=True". I suspect we
> would have to leave the default behavior as it is for continuity and
> backwards compatibility, although I think that changing it would be an
> improvement overall.
>
> Eric
>
>
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On 05/16/2010 10:19 AM, Philipp K. Janert wrote:
>
> Let's say I am running an interactive session
> (ipython -pylab), and now issue the following
> commands:
> 	
> 	x = linspace(0, 10, 100 )
> 	plot( x, sin(x) )
> 	ylim( -2, 2 )
> 	plot( x, cos(x) )
>
> Then the second plot command seems to reset
> the plot limits to [-1,1] - which makes sense for
> the figure, but is not what I requested.
>
> Is this behavior intended? It seems odd to me,
> since generally matplotlib seems to retain state
> that has between invocations of plot().
Good question. The control of autoscaling has a somewhat clunky 
interface via Axes methods, and via the plot function. Your two options 
are to follow the ylim call with the ugly
gca().set_autoscaley_on(False)
or to add a kwarg to all subsequent plot calls:
plot(x, cos(x), scaley=False)
A possible mpl improvement would be to add a kwarg to the pyplot.ylim 
and xlim functions, e.g.
ylim(-2, 2, keep=True)
Calling the kwarg "hold" would read better to my eye, but would conflict 
with the use of "hold" to mean "keep all prior plot elements". Maybe 
there is a better name, e.g. setting "auto=False" to mean "don't 
autoscale this on the next plot command". Or "save=True". I suspect we 
would have to leave the default behavior as it is for continuity and 
backwards compatibility, although I think that changing it would be an 
improvement overall.
Eric

Let's say I am running an interactive session 
(ipython -pylab), and now issue the following
commands:
	
	x = linspace(0, 10, 100 )
	plot( x, sin(x) )
	ylim( -2, 2 )
	plot( x, cos(x) )
Then the second plot command seems to reset
the plot limits to [-1,1] - which makes sense for 
the figure, but is not what I requested.
Is this behavior intended? It seems odd to me,
since generally matplotlib seems to retain state 
that has between invocations of plot().
Best,
		Ph.

 
Assume I am running an interactive session, using
 ipython -pylab
and have added a bunch of curves
 x = linspace(0, 10, 100 )
 plot( x, sin(x) )
 plot( x, cos(x) )
and also added a text label
 text( 1, 1, "Hello" )
But now I decide that I don't want the text anymore.
What's the best way to remove it from the graph?
(Because the graph is complicated I don't just want 
to clf() and start all over - I just want to remove that
one element.)
What I have found is that if I save the object created,
I can invoke its remove() function:
 t =text( 2, 1, "Hello again" )
 t.remove()
 draw()
Is this the best way to do this, or is there another way
(or one that does not require an explicit draw()?). Also,
what if I have failed to save the text instance - do I have
to walk the object tree using findobj()?
Thanks!
Best,
 Ph.

FIY, with the help of Sylvestre Ledru (debian atlas maintainer), the
problem was solved installing libatlas3g-sse*.

Hello,
I am writing a GUI using GTK+ library. I have a question about axes class imshow method memory consumption. If I pass the imshow an array, the resulting memory consuption is approximatelly 40 times greater than the array size. If I do not add the canvas to a window (in a code below), the memory consuption is as expected. Any tips on how to reduce the memory consuption would be very appreciated. Configuration and script are below.
os: Windowx XP
matplotlib version: 0.99.1
downloaded from: sourceforge.net
script:
from matplotlib.figure import Figure
from matplotlib.backends.backend_gtkagg import FigureCanvasGTKAgg
from pylab import rand
import gtk
window = gtk.Window()
window.connect("destroy", gtk.main_quit)
figure = Figure(figsize=(8,6), dpi=72)
canvas = FigureCanvasGTKAgg(figure)
axes = figure.add_subplot(111)
window.add(canvas)
axes.imshow(rand(1024,1024))
canvas.draw()
window.show_all()
gtk.main()
verbose-helpful output:
$HOME=C:\Documents and Settings\Sensej
CONFIGDIR=C:\Documents and Settings\Sensej\.matplotlib
matplotlib data path C:\Python26\lib\site-packages\matplotlib\mpl-data
loaded rc file C:\Python26\lib\site-packages\matplotlib\mpl-data\matplotlibrc
matplotlib version 0.99.1
verbose.level helpful
interactive is False
units is False
platform is win32
Using fontManager instance from C:\Documents and Settings\Sensej\.matplotlib\fontList.cache
backend GTKAgg version 2.12.1
findfont: Matching :family=sans-serif:style=normal:variant=normal:weight=normal:stretch=normal:size=medium to Bitstream Vera Sans (C:\Python26\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf) with score of 0.000000
Thank you,
Tomas.