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3d Surface from randomly distributed points

Dear Labview community,

 

I face a problem wich I could not resolve after hours of internet research and try & error. So I hope you can help me a bit for my bachelor-thesis 🙂

 

I have a huge set of randomly distributed points in spherical coordinates (phi, theta, r) resulting from my measurements. The distance between the points are not consistent. Plotting the data as a scatter-plot was no trouble but I actually want to plot the data as a surface, but so far without any results. 

 

I have read about interpolating the data to fill the gaps, but i dont really have a clue where to start or how to do that. 

 

I added two pictures of two scatterplots from my data, and the data-set from the first scatter-plot.

 

I'm looking forward to any input available. 

Thank you

 

 

 

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Message 1 of 5
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The Interpolate 2D Scattered VI might do what you want.  Here's an example which resamples a regular XY grid over your data.

 

Scattered2DInterpolation.png

Message 2 of 5
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Hello GredS

 

                    Can you please offer the complete file as shown on the picture? 

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Message 3 of 5
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It is a snippet, just drag&drop into an empty block diagram:
http://www.ni.com/tutorial/9330/en/
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Message 4 of 5
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The problem with your situation is that you do not have a "cloud of randomly-distributed points".  I'm assuming that you are plotting  a function of two variables, which I'll call X and Y.  You appear to "control" X and Y (which, in turn, implies that you "know" their value, with little measurement error) and are measuring Z = F(X, Y).  If you had chosen X and Y "at random" from, say, a unit square or from a unit circle, we might be able to "see" the resultant shape and would have a basis for talking about fitting a surface to it.

 

Instead, it looks like instead of taking a "random walk" inside the unit square, you hiked along a pre-define trail, covering certain parts of the domain very closely (the spacing between adjacent points is small) but having significant gaps between the various foot-paths.  Suppose I wanted to map out New York City, and I walked along the sidewalks, measuring the elevation every 100 feet (as opposed to throwing a dart at a map of the city and asking for the elevation wherever the dart hit).  Which method would you use to discover the topography of the city?

 

Bob Schor

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Message 5 of 5
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