matplotlib-users Mailing List for matplotlib

-- 
Jouni K. Seppänen
http://www.iki.fi/jks

Viraj Vajratkar wrote:
>
>
> On 7/3/07, *Jeff Whitaker* <js...@fa... 
> <mailto:js...@fa...>> wrote:
>
>     Michael Newman wrote:
>     > My understanding is the "contour" method only handles plots of
>     > functions, e.g. f(x,y) = z, and not discrete points. I tried looking
>     > into this weeks ago, and couldn't find a way to handle discrete
>     points.
>     >
>     > I'd love to be able to do Kriging or Inverse Distance Weighting
>     contour
>     > lines on XY points I have of pollution concentrations at various
>     monitors...
>     >
>     >
>     Michael:  There are three different methods for doing this
>     described at
>
>     http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data
>
>     -Jeff
>
>     --
>     Jeffrey S. Whitaker         Phone : (303)497-6313
>     NOAA/OAR/CDC  R/PSD1        FAX   : (303)497-6449
>     325 Broadway                Boulder, CO, USA 80305-3328
>
>
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> hey guys... i got it... u can use contour(x,y,z)... as in 
> x=load('urfile1.dat'), y=load('urfile2.dat), z=load('urfile3.dat 
> ').... and then type out the above.... for details about the 
> parameters x,y,z see... . 
> http://www.scilab.org/product/man-eng/graphics/contour.htm .... so 
> matplotlib CAN plot a contour from discrete points!!!.... ive tried it 
> and it works...
Viraj:  That only works because x and y describe a rectangular grid.  If 
x and y described irregularly spaced points, you would need to grid the 
data first using one of the methods described on that Cookbook page.

-Jeff

-- 
Jeffrey S. Whitaker         Phone : (303)497-6313
NOAA/OAR/CDC  R/PSD1        FAX   : (303)497-6449
325 Broadway                Boulder, CO, USA 80305-3328

On 7/3/07, Jeff Whitaker <js...@fa...> wrote:
>
> Michael Newman wrote:
> > My understanding is the "contour" method only handles plots of
> > functions, e.g. f(x,y) = z, and not discrete points. I tried looking
> > into this weeks ago, and couldn't find a way to handle discrete points.
> >
> > I'd love to be able to do Kriging or Inverse Distance Weighting contour
> > lines on XY points I have of pollution concentrations at various
> monitors...
> >
> >
> Michael:  There are three different methods for doing this described at
>
> http://www.scipy.org/Cookbook/Matplotlib/Gridding_irregularly_spaced_data
>
> -Jeff
>
> --
> Jeffrey S. Whitaker         Phone : (303)497-6313
> NOAA/OAR/CDC  R/PSD1        FAX   : (303)497-6449
> 325 Broadway                Boulder, CO, USA 80305-3328
>
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
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> Matplotlib-users mailing list
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> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
>
hey guys... i got it... u can use contour(x,y,z)... as in x=load('
urfile1.dat'), y=load('urfile2.dat), z=load('urfile3.dat').... and then type
out the above.... for details about the parameters x,y,z see... .
http://www.scilab.org/product/man-eng/graphics/contour.htm .... so
matplotlib CAN plot a contour from discrete points!!!.... ive tried it and
it works...

Dear All,

i'm displaying an image (cmap = gray, interpolation = nearest: i want to
see the pixels) and i plot point (markers) on top of the image. These
markers are calculated at the subpixel level so i want to zoom in to see
whether they are placed correctly.

When zooming in i notice two things:

1. at certain zoomlevels the image disappears (i do see the markers). At
other zoomlevels i see a tremendous change in brightness of the image.
Especcially at high zoomlevels i see this behaviour

2. when i zoom in a lot (selecting rectangle all over), the display gets
slower and slower... In the end, when viewing about 5x5 pixels or so it
becomes too slow...

Any ideas? I would love to use matplotlib (i really like it) but it
seems to have performance problems when displaying images is your main
concern.


Regards
Rein van den Boomgaard

(if needed i could send a zip file with programs and data)