Imagesc for triangular element

Question

Torkan 2019-2-3

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/442881-imagesc-for-triangular-element

评论： KSSV 2019-2-4

Hi,

I have a plate with mesh of triangular elements. I have specific number for each element. How can I use imagesc to have contourplot of those values? it is different from trisurf function of course?

Thanks

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

KSSV 2019-2-4

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/442881-imagesc-for-triangular-element#answer_359350

YOu can straight away plot contour with your data. Have a look in the following file exchange function: https://in.mathworks.com/matlabcentral/fileexchange/38858-contour-plot-for-scattered-data

If you want to use imagesc you have to convert your unstructured data into structured data either by using scatteredinterpolant or griddata.

7 个评论
显示 5更早的评论隐藏 5更早的评论

Walter Roberson 2019-2-4

The triangular element makes it a bit more difficult. Scattered interpolation works on the premise that the data is given for particular points and that there is some smooth transition to the values of other points that are given. Triangular elements, though, assert that the entire area within the triangle has a particular value, so to run a scattered interpolation you first have to subdivide the triangle into a number of sections each of which you approximate point-wise with the given value.

Triangular meshes are frequently used to model stresses and bending. The faces are not necessarily small and localized: they could end up large, or they could end up long and thin.

Depending on what is being modeled, variation in values are sometimes considered to be only along the edges, with the faces being considered to be rigid and inflexible. In such a case, a contour plot must follow edges: if there are two adjacent faces with different values, then a value between the two might not exist at some location between the two that is proportionate to the difference in value: the intermediate values might be considered to all exist simultaneously along the edges.

But there are certainly other cases where the intention is that the triangles are small and that taking them as point sources is fine, in which case plain scattered interpolation might be fine.

Thus we need to know more about the meaning of the triangulation to be sure of offering an appropriate solution.

Torkan 2019-2-4

Thanks

So, this function still available in MATLAB right? (2018) since while writing in MATLAB nothing is appeared for help.

Also, it gives us sth like imagesc, right? I mean colormap...

KSSV 2019-2-4

imagesc works on structured grids i.e matrices......tricontour will work....

请先登录，再进行评论。

Answer 2

Torkan 2019-2-4

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/442881-imagesc-for-triangular-element#answer_359353

walter thank you so much for detail

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。

Imagesc for triangular element

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

采纳的回答

7 个评论
显示 5更早的评论隐藏 5更早的评论

更多回答（1 个）

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

另请参阅

类别

标签

Community Treasure Hunt

Imagesc for triangular element

0 个评论 显示 -2更早的评论隐藏 -2更早的评论

采纳的回答

7 个评论 显示 5更早的评论隐藏 5更早的评论

更多回答（1 个）

0 个评论 显示 -2更早的评论隐藏 -2更早的评论

另请参阅

类别

标签

Community Treasure Hunt

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

7 个评论
显示 5更早的评论隐藏 5更早的评论

0 个评论
显示 -2更早的评论隐藏 -2更早的评论