Re: [Matplotlib-users] plotting a contour from dicrete data points

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