Interpolation of 3D point data
75 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
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 commentaires
Walter Roberson
le 20 Avr 2016
What properties does the curve need to have? Are you looking for a spline fit? A pchip fit?
Réponse acceptée
John D'Errico
le 29 Avr 2016
Modifié(e) : John D'Errico
le 29 Avr 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.
0 commentaires
Plus de réponses (2)
Walter Roberson
le 20 Avr 2016
It looks to me as if you likely want a scattered interpolant.
shellmcg
le 28 Avr 2016
1 commentaire
John D'Errico
le 28 Avr 2016
Modifié(e) : John D'Errico
le 29 Avr 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.
Voir également
Catégories
En savoir plus sur Interpolation dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!