My code is keep plotting the wrong data

2 views (last 30 days)
I have a 9 coloumns by 150 rows matrix and I have chosen three coloumns from it to form my new 3 comloumns matrix, so I chose second to be my Z (hight) and 8 and 9 to be my x and y respectively.
M = TEST(:,[8;9;2])
So, now I have a 3x150 Matrix and idealy it is 3 coloumns where first is X, second is Y and third is Z. Whenever I use surf. comand it plots wrong data and I am sure when I pick a plotted point it is all wrong. I do not know what to do to fix it.
and I do not want to plot a mathematical function I already have X Y and Z, and when I separate them, the code gives me an error that Z must be a matrix not vector, while it is obviously a matrix. I do not know how to solve it.

Accepted Answer

Star Strider
Star Strider on 7 Jul 2022
Perhaps —
TEST = randn(150,9);
M = TEST(:,[8 9 2]);
x = M(:,1);
y = M(:,2);
z = M(:,3);
L = size(M,1);
xv = linspace(min(x), max(x), L);
yv = linspace(min(y), max(y), L);
[Xm,Ym] = ndgrid(xv, yv);
Zm = griddata(x,y,z,Xm,Ym);
surf(Xm, Ym, Zm)
grid on
This should work with your data. It would help to have it to be certain.
Star Strider
Star Strider on 7 Jul 2022
My pleasure!
If my Answer helped you solve your problem, please Accept it!

Sign in to comment.

More Answers (1)

Jonas on 7 Jul 2022
may the scatter3() command is suffiecient to visualize your data, you interpolate (e.g. interp3) your XYZ data to generate more points and use surf() after that

Community Treasure Hunt

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

Start Hunting!

Translated by