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Re: Surface Smoothing

  • To: mathgroup at smc.vnet.net
  • Subject: [mg127621] Re: Surface Smoothing
  • From: "Kevin J. McCann" <kjm at KevinMcCann.com>
  • Date: Wed, 8 Aug 2012 03:15:04 -0400 (EDT)
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Any smoothing implicitly assumes that you "know" what the data should 
look like. So, I assume that you know that the spiky behavior is not 
"correct". Given that, how about a LSQ fit to some satisfactorily smooth 
function, e.g. a 2d polynomial or a truncated Fourier series?

Kevin

On 8/6/2012 4:50 AM, Nicholas Kormanik wrote:
> This is a follow-up to a post I made last week (included at bottom).
>
> My ListPlot3D output is pretty spiky, with spikes extending above and below.
> Quite hard to get a sense where any "sweet spots" might exist -
> "neighborhood average" relatively high.
>
> I've looked into using the various forms of Interpolate.  None of those will
> "smooth the surface," as they all require passing through the original data
> points.
>
> I'm wondering if any of you might know of a third-party Mathematica package
> that will do surface smoothing?
>
> Please guide me to such package, if you do.  Or if you know of another
> approach that'll get the job done.
>
> Thanks,
>
> Nicholas
>
>
> From: Nicholas Kormanik [mailto:nkormanik at gmail.com]
> Sent: Friday, August 03, 2012 1:04 AM
> To: 'mathgroup at smc.vnet.net'
> Subject: ListContourPlot
>
>
>
>
>
> I've been attempting to create a contour plot within Mathematica 8.04.
>
>
>
> I posted to the Mathematica StackExchange, but didn't get a conclusive
> answer:
>
>
>
> http://mathematica.stackexchange.com/questions/8821/creating-optimal-smoothe
> d-contour-type-plots-x-y-z-using-mathematica-8-04
>
>
>
> Hopefully someone here can assist.
>
>
>
> Here is a link to the data file:
>
>
>
> http://rapidgator.net/file/29594247/20201_23405_50502.XLS.html
>
>
>
> Here is a link to an example contour plot, made in another program (SAS):
>
>
>
> http://rapidgator.net/file/29594680/50502_20201_23405.png.html
>
>
>
> In case the files do not make it through to you, the data file is an Excel
> .xls file with three columns, X,Y,Z.  Z in the contour plot would be shown
> by contours or a gradient of colors.
>
>
>
> If a contour plot isn't possible, perhaps ListPlot3D?
>
>
>
> The process is far from straight-forward.  Definitely a learning curve
> involved.
>
>
>
> Unfortunately the Mathematica documentation almost exclusively gives
> examples using functions and distributions, not standard data columns for
> input.
>
>
>
> Thanks,
>
> Nicholas Kormanik
>
>
>




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