[Matplotlib-users] Interpolation method of python matplotlib contourf

[vincent.adrien at gmail.com]

Hi all,

Sakis, are you saying that if the (linear) interpolation scheme was simply mentionned in the relevant docstring (I imagine some place like `matplotlib.axes.contour{f}` or `matplotlib.contour.{Quad}ContourSet`), then it would be enough regarding your need for a reference? I guess that a quick PR to fix what seems to be a small yet quite unfortunate
hole in the documentation anyway would be welcome, would it not?

Best regards,
Adrien

Le 02/02/2021 à 14:49, Athanasios Karagiannidis a écrit :
> 
> Hello again Ian
> 
> I can work with linear, no problem!
> 
> Regarding, the reference: The link may not be sufficient. I depend.  I guess I may have to find a general reference for the linear interpolation to incorporate in my manuscript.
> 
> Thank you very much!
> 
> Best regards
> 
> Sakis
> 
> Athanasios F. Karagiannidis
> Physicist, PhD Meteorology and Climatology
> E-mail: thankar at live.com
> 
> 
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> *From:* Ian Thomas <ianthomas23 at gmail.com>
> *Sent:* Tuesday, February 2, 2021 2:44 PM
> *To:* Athanasios Karagiannidis <thankar at live.com>
> *Cc:* matplotlib-users at python.org <matplotlib-users at python.org>
> *Subject:* Re: [Matplotlib-users] Interpolation method of python matplotlib contourf
>  
> Hi Sakis,
> 
> No, you cannot control the interpolation method, you are stuck with linear for now.  It is on my wishlist for future improvements, but this is no help to you now.
> 
> To demonstrate that it is linear interpolation I would reference the code, e.g. https://github.com/matplotlib/matplotlib/blob/ea6803254567eaaa9adb027b541a6885d9fa246f/src/_contour.cpp#L1345-L1354 <https://github.com/matplotlib/matplotlib/blob/ea6803254567eaaa9adb027b541a6885d9fa246f/src/_contour.cpp#L1345-L1354> is the C++ interpolation function which is self-evidently linear interpolation.  I am not sure if that link is good enough for a manuscript though.
> 
> Ian
> 
> On Tue, 2 Feb 2021 at 12:22, Athanasios Karagiannidis <thankar at live.com <mailto:thankar at live.com>> wrote:
> 
>     Hello Ian
> 
>     Another interpolation may come handy in the future. Is it possible to control the interpolation method?
> 
>     The fact that the current interpolation method is not documented is a pity. I need to reference it in a manuscript...
> 
>     Sakis
> 
>     Athanasios F. Karagiannidis
>     Physicist, PhD Meteorology and Climatology
>     E-mail: thankar at live.com <mailto:thankar at live.com>
> 
> 
>     ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
>     *From:* Ian Thomas <ianthomas23 at gmail.com <mailto:ianthomas23 at gmail.com>>
>     *Sent:* Tuesday, February 2, 2021 1:17 PM
>     *To:* Athanasios Karagiannidis <thankar at live.com <mailto:thankar at live.com>>
>     *Cc:* matplotlib-users at python.org <mailto:matplotlib-users at python.org> <matplotlib-users at python.org <mailto:matplotlib-users at python.org>>
>     *Subject:* Re: [Matplotlib-users] Interpolation method of python matplotlib contourf
>      
>     Hello Sakis,
> 
>     All of Matplotlib's contouring functions (contour, contourf, tricontour, tricontourf) use linear interpolation along grid edges.  This is not explicitly documented anywhere.
> 
>     Are there other interpolation options that you would like?  I can think of logarithmic as one possibility.
> 
>     Ian
> 
>     On Tue, 2 Feb 2021 at 10:08, Athanasios Karagiannidis <thankar at live.com <mailto:thankar at live.com>> wrote:
> 
>         Hello to all
> 
>         I want to ask what is the default interpolation method of python matplotlib contourf? Where can I find relative documentation? Could someone help me?
> 
>         Best regards
> 
>         Sakis
> 
>         Athanasios F. Karagiannidis
>         Physicist, PhD Meteorology and Climatology
>         E-mail: thankar at live.com <mailto:thankar at live.com>
> 
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