matplotlib-users Mailing List for matplotlib

Hello,
I'm trying to plot a simple list of x/y coords over an image (.png). I can
show the image, or plot the data, but cannot find a way to layer one over
the other. I would greatly appreciate someone pointing me in the right
direction. Thanks.

Mark,
 As a quick workaround, try
rcParams['contour.negative_linestyle']=(6, 0)
This is a hack--using dashes with zero-length spaces.
I expect to have a better solution in svn shortly.
Eric
Mark Bakker wrote:
> Hello -
> 
> I tried to turn of the feature that makes contours with negative values 
> dashed.
> According to the mailinglist this should go by setting: 
> rcParams['contour.negative_linestyle']=('None','None')
> I tried any combination of the None, None syntax, or just 'solid', but 
> nothing worked.
> Example shown below. I am using 0.90.1.
> Thanks, Mark
> 
> from pylab import *
> x,y = meshgrid(linspace(-3,3,10),linspace(-3,3,10))
> rcParams['contour.negative_linestyle']=('None','None')
> contour(x,y,x,colors='b')
> 
> Error message:
> 
> Traceback (most recent call last):
> File "<pyshell#10>", line 1, in ?
> contour(x,y,x,colors='b')
> File "C:\Python24\Lib\site-packages\matplotlib\pylab.py", line 1777, 
> in contour
> draw_if_interactive()
> File 
> "C:\Python24\Lib\site-packages\matplotlib\backends\backend_tkagg.py", 
> line 59, in draw_if_interactive
> figManager.show()
> File 
> "C:\Python24\Lib\site-packages\matplotlib\backends\backend_tkagg.py", 
> line 311, in show
> self.canvas.draw()
> File 
> "C:\Python24\Lib\site-packages\matplotlib\backends\backend_tkagg.py", 
> line 154, in draw
> FigureCanvasAgg.draw(self)
> File 
> "C:\Python24\Lib\site-packages\matplotlib\backends\backend_agg.py", line 
> 392, in draw
> self.figure.draw(renderer)
> File "C:\Python24\Lib\site-packages\matplotlib\figure.py", line 601, 
> in draw
> for a in self.axes: a.draw(renderer)
> File "C:\Python24\Lib\site-packages\matplotlib\axes.py", line 1286, in 
> draw
> a.draw(renderer)
> File "C:\Python24\Lib\site-packages\matplotlib\collections.py", line 
> 700, in draw
> transoffset)
> ValueError: invalid literal for float(): None
> 
> 
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Hi all,
First, sorry for the crossposting. I have drafted a small document (it
is in Spanish, if there's interest, I'll have a go at translating it)
on how to use OGR from Python access geospatial data, which can be
further analysed or plotted with matplotlib. It is a very brief
introduction, and surely there is much to improve, but I was looking
for something like this for a while, and couldn't find it.
The page is here: <http://jgomezdans.googlepages.com/ogr%2Cpythonymatplotlib>
Cheers,
jose

Hello -
I tried to turn of the feature that makes contours with negative values
dashed.
According to the mailinglist this should go by setting: rcParams['
contour.negative_linestyle']=('None','None')
I tried any combination of the None, None syntax, or just 'solid', but
nothing worked.
Example shown below. I am using 0.90.1.
Thanks, Mark
from pylab import *
x,y = meshgrid(linspace(-3,3,10),linspace(-3,3,10))
rcParams['contour.negative_linestyle']=('None','None')
contour(x,y,x,colors='b')
Error message:
Traceback (most recent call last):
 File "<pyshell#10>", line 1, in ?
 contour(x,y,x,colors='b')
 File "C:\Python24\Lib\site-packages\matplotlib\pylab.py", line 1777, in
contour
 draw_if_interactive()
 File "C:\Python24\Lib\site-packages\matplotlib\backends\backend_tkagg.py",
line 59, in draw_if_interactive
 figManager.show()
 File "C:\Python24\Lib\site-packages\matplotlib\backends\backend_tkagg.py",
line 311, in show
 self.canvas.draw()
 File "C:\Python24\Lib\site-packages\matplotlib\backends\backend_tkagg.py",
line 154, in draw
 FigureCanvasAgg.draw(self)
 File "C:\Python24\Lib\site-packages\matplotlib\backends\backend_agg.py",
line 392, in draw
 self.figure.draw(renderer)
 File "C:\Python24\Lib\site-packages\matplotlib\figure.py", line 601, in
draw
 for a in self.axes: a.draw(renderer)
 File "C:\Python24\Lib\site-packages\matplotlib\axes.py", line 1286, in
draw
 a.draw(renderer)
 File "C:\Python24\Lib\site-packages\matplotlib\collections.py", line 700,
in draw
 transoffset)
ValueError: invalid literal for float(): None

Hi,
I want to plot some timeseries (eg. stockcharts). I use now 
DateLocator/Formatter, it works fine for me with the exeption, that 
dataless periods on X-Axis (eg. weekends) are also plotted. Is there an 
easy way to suppress them?
regards