Re: [Matplotlib-users] contourf interpolation/smoothness

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

P.R. wrote:
> Jeff,
> One more question:
> Given two arbitrary X&Y arrays, what's the easiest/fastest way to convert to
> a finer array ?
> (for example, convert a 0.5 degree 'X' or 'Y' array to a 0.25 array over the
> same bounds as the original array)
>
> - I need a method that can handle arbitrary grid sizes & resolutions, so I
> can't just hard-code the X&Y sizes for the finer grid.
>
> Any ideas?
>
> Thanks,
> P.Romero
>   
P.R.  The interp function can do that easily, you just create an array 
of lats and lons defining the output grid by dividing the input grid 
size by 2.  Is there something in the docstring that is not clear?

-Jeff
> -----Original Message-----
> From: Jeff Whitaker [mailto:js...@fa...] 
> Sent: 2009-08-13 7:15 AM
> To: Eric Firing
> Cc: P.R.; mat...@li...
> Subject: Re: [Matplotlib-users] contourf interpolation/smoothness
>
> Eric Firing wrote:
>   
>> P.R. wrote:
>>   
>>     
>>> This has probably been asked before, so I apologize...
>>>
>>> Is it possible to improve the smoothness/interpolation used in contourf?
>>> I know that the interpolation can be set for imshow(pcolor?), but I
>>>       
> couldn't
>   
>>> see how to set it for contourf.
>>>
>>> Right now, contourf is producing some relatively jagged output for my
>>> dataset, and I'd like to try to smoothen it out, without resorting to
>>>       
> using
>   
>>> pcolor/imshow...
>>>     
>>>       
>> There are two approaches:
>>
>> 1) manipulate the contours (the patch boundaries)
>> 2) smooth and interpolate the data to a finer grid before contouring.
>>
>> There are many problems with the first approach, and we have never tried 
>> to implement it.
>>
>> That leaves the second method, which is really not a plotting task but a 
>> data processing task.  You might want to see if there is a suitable tool 
>> in scipy.
>>
>> Eric
>>
>>
>>   
>>     
> Pablo:  You could use the interp function in Basemap to bilinearly 
> interpolate to a finer grid.
>
> http://matplotlib.sourceforge.net/basemap/doc/html/api/basemap_api.html#mpl_
> toolkits.basemap.interp
>
> -Jeff
>
>   


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