Interpolate values triangular prism mesh on unstructured tetrahedral mesh

Question

Sarah Garre 2016-7-25

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/297119-interpolate-values-triangular-prism-mesh-on-unstructured-tetrahedral-mesh

评论： Sarah Garre 2016-7-26

I am trying to interpolate the values of a fine structured triangular prism (=wedge) mesh on a coarser unstructured tetrahedral mesh. For both meshes, I have the x,y,z coordinates of the cell center, so in principle it is just a question of finding the x nearest neighbors of the coarse mesh and assign a weight average of the values of these points to the tetrahedron of the coarse mesh. I actually thought this would be possible with the interp3 function, but it gives me an error message stating that my values are not monotonously increasing. Any clue on how I can efficiently to this interpolation job? Best regards and thanks in advance for your help. Sarah

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

John D'Errico 2016-7-25

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/297119-interpolate-values-triangular-prism-mesh-on-unstructured-tetrahedral-mesh#answer_229722

interp3 is not designed to solve an interpolation on a scattered set. It REQUIRES a regular, rectangular mesh. If you lack that, then it won't work. Anyway, just finding the nearest set of k neighbors is a bad way to do interpolation, since it need not yield a continuous prediction.

You need to use tools like scatteredInterpolant, or if you already have the tessellated mesh, then something like tsearchn.

3 个评论
显示 1更早的评论隐藏 1更早的评论

John D'Errico 2016-7-26

In three dimensions, a tessellated mesh would be that 4 column array of indices for the tetrahedral mesh. Each row of that array indicates one tetrahedron of the mesh. It is the array TRI in the call to tsearchn. Likewise, the existing mesh node coordinates will be the array X in your call to tsearchn.

Sarah Garre 2016-7-26

Hi John, I tested your first option with scatteredInterpolant and it seems to work and even fairly fast... F = scatteredInterpolant(MeshHYD.cellmid(:,1),MeshHYD.cellmid(:,2),MeshHYD.cellmid(:,3),MeshHYD.WC(:,ii)); MeshBERT.WC(:,ii) = F(MeshBERT.cellmid(:,1),MeshBERT.cellmid(:,2),MeshBERT.cellmid(:,3)); I'll see whether I can make the other option work too. Thanks for your help!

请先登录，再进行评论。