Unique quad element list

2 次查看（过去 30 天）
ConvexHull
ConvexHull 2020-7-8
编辑： ConvexHull 2020-7-8
Dear all,
i am stuck with a small (easy) problem and need a hint.
Consider you have a non-unique element list t_quad with size(n_quad,4) and a corresponding non-unique point list p_quad with size(n_points,2).
Moreover, the point list also contains points which are never indexed by the element list.
I want to make both lists unique meaning i want to have a t_quad_unique list and a p_quad_unique list:
% Works!: This removes the non-unique elements and the corresponding points
[t_quad,~,~]=unique(t_quad,'rows');
[p_quad,~,b]=unique(p_quad,'rows');
t_quad(:)=b(t_quad(:));
Then after this i want to remove also the non-used points which are never used by the element list:
% Does not work!
[p_quad,~,b]=unique(p_quad(t_quad(:),:),'rows');
t_quad(:)=b(t_quad(:));
I lose some informations in this step. Where is the mistake?
Thanks for your help!
Edit:
Before:
After:
  6 个评论
显示 4更早的评论
ConvexHull
ConvexHull 2020-7-8
编辑：ConvexHull 2020-7-8
Note that the minimal example is quite specific. The non-used random points may be located arbitrary in the point list.
ConvexHull
ConvexHull 2020-7-8
编辑：ConvexHull 2020-7-8
Note that the point ordering inside an element
t_quad(:,1) --> t_quad(:,2) --> t_quad(:,3) --> t_quad(:,4)
should be preserved.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

ConvexHull
ConvexHull 2020-7-8
编辑：ConvexHull 2020-7-8
I answer my own question. This should work:
[t_quad,~,~]=unique(t_quad,'rows');
[p_quad,~,b]=unique(p_quad,'rows');
t_quad(:)=b(t_quad(:));
[p_unique,~,~]=unique(p_quad(t_quad(:),:),'rows');
[~,c]=ismember(p_quad,p_unique,'rows');
p_quad=p_unique;
t_quad(:)=c(t_quad(:));
Thanks anyway!

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Operators and Elementary Operations 的更多信息

标签

产品


版本

R2018b

Community Treasure Hunt

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

Start Hunting!

Translated by