[ncl-talk] What is the spatial interpolation method used by "contouring 1-D data"?

[Wenshan Wang]

Great!
Thank you, Mary!
Thank you, Dennis!

Best,
Wenshan
------------------------------------------------------------------------------
Post-doctoral Scholar
Zender Research Group
Department of Earth System Science
University of California, Irvine
https://sites.google.com/a/uci.edu/wenshanwang/


On Wed, Oct 10, 2018 at 7:57 PM Mary Haley <haley at ucar.edu> wrote:

> Hi Wenshan,
>
> You're right that the code that does the Delaunay mesh is "triangle.c",
> and the code that calls it is in CnTriMeshRenderer.c.  Look for places
> where you see:
>
> #ifdef BuildTRIANGLE
> . . .
> #endif
>
> and this will show you the code that is calling the triangle code.
>
> Note that the triangle.c, triangle.h files are from Jonathan Shewchuk of
> Berkeley, and you can find out more about the code at:
>
> http://www.cs.cmu.edu/~quake/triangle.html
>
> --Mary
>
>
>
> On Wed, Oct 10, 2018 at 5:04 PM, Wenshan Wang <wenshanw at uci.edu> wrote:
>
>> Hi Dennis,
>>
>> Thank you for the reply!
>> I am so sorry for the delay. I was traveling.
>>
>> What I tried to understand is the following description of
>> contour1d_1.ncl on the webpage 'Contouring one-dimensional X, Y, Z (random)
>> data' (https://www.ncl.ucar.edu/Applications/contour1d.shtml):
>> "By default, NCL will generate smoothed contours (see first frame) in an
>> area enclosed by a convex hull
>> <https://en.wikipedia.org/wiki/Convex_hull>of the data".
>>
>> Based on the links you included and a little digging into the NCL code,
>> is it safe to say that:
>> 1, the smoothing method is: cubic spline interpolation
>> 2, the convex hulls are created using the Delaunay triangulation (the
>> dual of Voronoi diagram) by calling 'triangle'?
>> But I didn't find the actual calling commands in NCL code.
>>
>> Best,
>> Wenshan
>>
>> ------------------------------------------------------------------------------
>> Post-doctoral Scholar
>> Zender Research Group
>> Department of Earth System Science
>> University of California, Irvine
>> https://sites.google.com/a/uci.edu/wenshanwang/
>>
>>
>> On Sun, Sep 16, 2018 at 3:14 PM Dennis Shea <shea at ucar.edu> wrote:
>>
>>> Without going into the code, a guess would be:
>>> *http://ngwww.ucar.edu/supplements/conpack/#Intro2DSmoothing*
>>> <http://ngwww.ucar.edu/supplements/conpack/#Intro2DSmoothing>
>>> *http://ngwww.ucar.edu/supplements/dashpack/*
>>> <http://ngwww.ucar.edu/supplements/dashpack/>
>>> Correct:  it is not "simple 9-point smoothing"
>>> ====
>>> Not sure what you mean by: "Triangulated irregular networks"
>>>
>>> * http://www.cs.cmu.edu/~quake/triangle.
>>> <http://www.cs.cmu.edu/~quake/triangle.html>html
>>> <http://www.cs.cmu.edu/~quake/triangle.html>*
>>> <http://www.cs.cmu.edu/~quake/triangle.html>
>>>
>>>
>>>
>>> *https://www.ncl.ucar.edu/Document/Graphics/contour_grids.shtml
>>> <https://www.ncl.ucar.edu/Document/Graphics/contour_grids.shtml>*
>>>
>>>
>>> <http://www.cs.cmu.edu/~quake/triangle.html>
>>>
>>>
>>> On Wed, Sep 12, 2018 at 4:16 PM, Wenshan Wang <wenshanw at uci.edu> wrote:
>>>
>>>> Hi NCL-talk,
>>>>
>>>> What is the spatial interpolation method used in this example
>>>> contour1d_1.ncl?
>>>> Is it "Triangulated irregular networks"?
>>>> Where can I find a more detailed description?
>>>>
>>>> Also, what is the smoothing method here?
>>>> seems not a simple 9-point smoothing.
>>>>
>>>> Thank you!
>>>>
>>>> Best,
>>>> Wenshan
>>>>
>>>> ------------------------------------------------------------------------------
>>>> Post-doctoral Scholar
>>>> Zender Research Group
>>>> Department of Earth System Science
>>>> University of California, Irvine
>>>> https://sites.google.com/a/uci.edu/wenshanwang/
>>>>
>>>> _______________________________________________
>>>> ncl-talk mailing list
>>>> ncl-talk at ucar.edu
>>>> List instructions, subscriber options, unsubscribe:
>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>
>> _______________________________________________
>> ncl-talk mailing list
>> ncl-talk at ucar.edu
>> List instructions, subscriber options, unsubscribe:
>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20181011/cc076cf5/attachment.html>