The query points have inconsistent spatial dimension

Hi,

I have a triangular mesh, and I am trying to obtain the triangle indices at picked point locations.

tri = triangulation(data.econn,data.r);

disp(['Pick ',num2str(Npts),'query points . . .']);

p0=ginput(Npts); 
x0=p0(:,1); y0=p0(:,2);

scatter(x0,y0, 'filled') %visualize query points 
pointLocation(tri,x0,y0); %Error using triangulation/pointLocation: %The query points have inconsistent spatial dimension.

Whatever location I choose, I end up with the same error:

Error using triangulation/pointLocation

The query points have inconsistent spatial dimension.

x0 and y0 are column-vectors of the same size... Can someone indicate what's wrong with my code?

Thank you!

Answer 1

[Shivam]

Hi,

From the information provided, I understand that you are getting an error while executing pointLocation(tri, x0, y0) with 'tri' as the triangulation object and 'x0' and 'y0' as coordinates obtained from ginput.

The error occurs because the 'pointLocation' function expects the query points to have the same number of dimensions as the triangulation object. Here, the query points, i.e., (x0, y0), are 2-D and 'tri' is 3-D.

>> tri

tri = 
    triangulation with properties:
              Points: [542×3 double]
    ConnectivityList: [984×3 double]

In this case, you can delete the third column of data.r to get the 2-D triangulation object, considering z-coordinate for every point is 0:

data.r(:,3) = [];

>> tri

tri = 
    triangulation with properties:
              Points: [542×2 double]
    ConnectivityList: [984×3 double]

You can refer to the following documentation to know more about ginput, triangulation and pointLocation:

1. https://www.mathworks.com/help/releases/R2023a/matlab/ref/ginput.html
2. https://www.mathworks.com/help/releases/R2023a/matlab/ref/triangulation.html
3. https://www.mathworks.com/help/releases/R2023a/matlab/ref/triangulation.pointlocation.html

I hope it helps in resolving the error.

Thanks,

Shivam

[biot0p]

Hi, that makes a lot of sense! thank you.