plot plane through set of 3d point

5 views (last 30 days)
ha ha
ha ha on 28 Feb 2018
Edited: ha ha on 1 Mar 2018
Let's say : I have a set of 3d data (x,y,z) from experiment
data=[x1 y1 z1
x2 y2 z2
x3 y3 z3
x4 y4 z4
I want to plot the plane contain all points by total least square method. The result as follow. How can I plot like sample illustration?

Answers (1)

Roger Stafford
Roger Stafford on 28 Feb 2018
Edited: Roger Stafford on 28 Feb 2018
If X, Y, and Z are vectors of the x,y,z coordinates of your points, do this:
dX = X-mean(X);
dY = Y-mean(Y);
dZ = Z-mean(Z);
XX = sum(dX.^2); YY = sum((dY.^2; ZZ = sum(dZ.^2);
XY = sum(dX.*dY); XZ = sum(dX.*dZ); YZ = sum(dY.*dZ);
A = [XX,XY,XZ;
[V,D] = eig(A); % <--Corrected
[~,k] = min(diag(D));
V(1,k)*(x-mean(X))+V(2,k)*(y-mean(Y))+V(3,k)*(z-mean(Z)) = 0 % <--Corrected
where V(:,k) is the eigenvector of A with the smallest eigenvalue, and gives the equation for the best fit plane through your points. (Note: The lowercase x, y, and z here refer to coordinates of the equation of the plane.)
You can plot this plane by using an appropriate meshgrid of x,y points along with solving for z in the plane equation making use of the 'surf' command.
ha ha
ha ha on 28 Feb 2018
Can you help me to perform it by using the attached data "ha.txt"

Sign in to comment.


Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!