Compare two matrices/meshgrid/surface/ model digital - distance between models - point data - 3D mesh

10 次查看（过去 30 天）

显示更早的评论

Octavian Macari 2018-5-23

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/402127-compare-two-matrices-meshgrid-surface-model-digital-distance-between-models-point-data-3d-mes

评论： Nicola Bombace 2018-5-29

采纳的回答： Nicola Bombace

17may18.mat

I have 3 vectors fo each surface (meshgrid). I want to compare the distance between this to surfaces. The problem is that to surfaces are not in the same position and the cells of the meshgrid are not on the same size. What i can do to obtain the correct distance between of this tow models?

surf(X,Y,Z); hold on; grid on; hold on, scatter3(NF_P(:,1),NF_P(:,2),NF_P(:,3),'filled'); surfl(X2A,Y2A,Z2A); hold on; scatter3(DD_B2(:,1),DD_B2(:,2),DD_B2(:,3)*(-1),'filled')

i want the difrence between Z and Z2A, but X and Y are difrent from X2A and Y2A.

i make Z3=Z-Z2A, bu is not correct that giv me difrences of 4 meters , that is not true, soo i dont know how to make this analyse

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。

采纳的回答

Nicola Bombace 2018-5-23

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/402127-compare-two-matrices-meshgrid-surface-model-digital-distance-between-models-point-data-3d-mes#answer_321546

编辑：Nicola Bombace 2018-5-23

在 MATLAB Online 中打开

The first thing you want to do is interpolate the data from one surface to be at the x,y position of the second surface. Then compute the distance from the interpolated surface

Z_int = griddata(X,Y,Z,X2A,Y2A); %interpolate surface 1 to match x,y coordinates of surface 2              
Z3 = Z_int - Z2A;

Just two more comments

Obviously you can think about starting from surface 2 to match the x and y of surface 1. The difference in the result should be negligible, but this depends on the data.
I would suggest another measure of the distance, because you can imagine that if the two surfaces cross each other you could have a distance of zero, when actually is not. I would square the difference vector and take its square root as a first attempt.

Hope this helps

6 个评论
显示 4更早的评论隐藏 4更早的评论

Octavian Macari 2018-5-24

We have programs that do that but all it is payed and not accessible, more for hydrografic institution, like "CARIS HIPS & SHIPS". My thesis is based on creat a metodology to process the data.

Nicola Bombace 2018-5-29

The issue of cleaning the points is not trivial. I can suggest an algorithm, rather than a specific implementation, and hopefully it will be easy to implement.

Construct the Mesh with the original points using the delaunayn function
Determine if a query point is inside your delaunay triangulation using pointLocation function

请先登录，再进行评论。

更多回答（1 个）

Octavian Macari 2018-5-27

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/402127-compare-two-matrices-meshgrid-surface-model-digital-distance-between-models-point-data-3d-mes#answer_322167

Hello, About what you suggest, "I would suggest another measure of the distance, because you can imagine that if the two surfaces cross each other you could have a distance of zero, when actually is not. I would square the difference vector and take its square root as a first attempt."

did you mean something like that: Zsq = sqrt(Z.^2 - Z2A.^2); that give-me error, i have the matriz with i value

(...2.3032 + 0.0000i ; NaN + 0.0000i ; NaN + 0.0000i ; NaN + 0.0000i ...)

i can´t figure what you sugest