Re: [Matplotlib-users] Contouring a large set of ungridded data

[Jeff W. <js...@fa...>]

Jesper Larsen wrote:
> On Saturday 15 October 2005 01:10, Jeff Whitaker wrote:
>   
>> Jesper:  Since this question has come up a couple of times, I decided to
>> cook up an example.  First you'll need to download and install the
>> natgrid python module (included in CDAT, but I've separated it out from
>> the huge tarball and put it at
>> ftp://ftp.cdc.noaa.gov/Public/jsw/natgrid.tar.gz).  Then try this:
>>     
>
> Sounds great. I tried your example and it works fine (though I had to modify 
> the import nat statement to "from natgrid import nat").
>
> The only problem for my application is that I would like the interpolation to 
> be limited to areas near observations and avoiding extrapolation to areas far 
> from observations. Is that possible - from the natgrid documentation that 
> does not seem to be the case?
>   

Jespers:  You can tell natgrid to not do any extrapolation outside the 
convex hull defined by the data points - see test.py in 
ftp://ftp.cdc.noaa.gov/Public/jsw/natgrid-0.1.tar.gz.  In that example I 
create a masked array that is only defined where there is no 
extrapolation needed.

-Jeff


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