What makes the difference between griddata and griddatan?

2 views (last 30 days)
Peng Liu
Peng Liu on 2 Feb 2017
Commented: Honglei Chen on 3 Feb 2017
Since griddatan is the n-d generalization of griddata, I assume that for 2-d scenarios, they should have identical behavior. This is true for most cases. For example:
uv = [-6,-13;-3,-9;-9,-2;-12,7;25,-14;16,-24;3,15];
xy = [8,6;15,1;4,-11;-3,9];
z1 = griddata(uv(:,1),uv(:,2),uv(:,2),xy(:,1),xy(:,2))
z2 = griddatan(uv,uv(:,2),xy)
The output is:
z1 =
6.0000
NaN
-11.0000
9.0000
z2 =
6.0000
NaN
-11.0000
9.0000
But in the following example, griddata gives valid output while griddatan fails.
uv = [0,0;0,2;2,2;2,0];
xy = [1,1;3,1];
z1 = griddata(uv(:,1),uv(:,2),uv(:,2),xy(:,1),xy(:,2))
z2 = griddatan(uv,uv(:,2),xy)
The error message indicates that some internal check of the convex hull in griddatan fails. But why is that? Why griddata run without a similar convex check? Thanks.
  1 Comment
Honglei Chen
Honglei Chen on 3 Feb 2017
I'd suggest you report this to MathWorks. Regardless of the reason, you certainly should get a better error message.

Sign in to comment.

Answers (0)

Products

Community Treasure Hunt

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

Start Hunting!

Translated by