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3D best fit tendline

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knfs

Aerospace
May 19, 2006
2
Help much appreciated;

When using griddata and meshgrid to produce a 3D plot is there anyway to fit a trendline rather than just interpolate between the results.

Currently the experimental data used produces a somewhat 'wavey' plot. It would be much improved if a smoother plot could be achieved by fitting a surface through the data rather than interpolating between results.

Thanks
 
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i don't know how to do you are asking for, but ...

your data won't be improved by adding a trend line ...

the presentation of your data might, but then maybe the "waviness" is an important technical detail.
 
The experimental data i have shows some noise in the signal. A trendline would help to reduce the impact of this on the plot and allow a more 'useful' plot to be drawn.

comments welcomed
 
Report the data on Excel and go to the ‘Chart’ menu and click on the ‘Add Trendline’ option.
Click the ‘Options’ tab in the window . Check the ‘Display equation on chart’ option and click ‘OK’. This plots a linear fit and gives the slope and the offset of the fit.
 
Search the Web for "Data Smoothing." Mostly you'll find 2D info but these can be extended to work with surfaces.
 
Why not do the trendline in slices?

Smoothing data.. must be a NASA thing?




 
A couple of elementary data smoothing techniques are

Best Fit Straight Line (linear regression).

Moving Average Filter.
 
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