Interpolation of 3D point data
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Hello, I have a nx5 matrix where column 3, 4 and 5 are x,y,z 3D points respectively. I was wondering how I would interpolate (smooth) this 3D data. Many thanks
4 Commenti
Walter Roberson
il 20 Apr 2016
What properties does the curve need to have? Are you looking for a spline fit? A pchip fit?
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John D'Errico
il 29 Apr 2016
Modificato: John D'Errico
il 29 Apr 2016
You can use my interparc tool, as found on the file exchange. It is designed to solve exactly this problem, in 2 or more dimensions.
xyz = interparc(1000,x,y,z,'spline');
xyz will be a 1000x3 array, where each row is an interpolated point on the curve.
Of course, you can do the interpolation in other ways. If you want to do the work in MATLAB yourself in much the same way as you tried to do it:
t = [0;cumsum(sqrt(diff(x).^2+diff(y).^2+diff(z).^2))];
t = t/t(end);
ti = linspace(0,1,1000);
xx = spline(t,x,ti);
yy = spline(t,y,ti);
zz = spline(t,z,ti);
The above solution, which uses a cumulative piecewise linear arclength as the parameter for interpolation, deals more properly with points that are not uniformly spaced.
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Più risposte (2)
Walter Roberson
il 20 Apr 2016
It looks to me as if you likely want a scattered interpolant.
shellmcg
il 28 Apr 2016
1 Commento
John D'Errico
il 28 Apr 2016
Modificato: John D'Errico
il 29 Apr 2016
I'm sorry, but this answer is just a poor way of solving the problem, presuming the points are somehow equally spaced. Use of a spline as was done here can cause some strange artifacts.
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