Boundary is called on vertices

[AJAXJR24]

I am trying to solve a problem over a Rectangle Geometry. my rectangle min and max are [0,0], [1,1]. I get the below error:

Warning: Rectangle boundary_normal called on vertices. You may use PDE(..., exclusions=...) to exclude the vertices. Warning: Rectangle boundary_normal called on vertices. You may use PDE(..., exclusions=...) to exclude the vertices.

When I want to define exclusions by an array I also get an error. I assume because my problem is 3D(x,y,t), The exclusions array elements must be the shape of my dimensions. If I am right, How should it be defined since there is time in my problem?

[unixcrab]

I am also getting these warnings, but for a 2D time dependent PDE. Would like to know how to solve it. Mine converges very well so I'm not sure if this warning is affecting anything.

[lululxvi]

This warning means that the code tries to compute the normal direction for vertices, which is not well defined. In many cases, this would not cause a problem, and you can ignore the warning.

When you want to exclude the points, then you are right that the points should be the same shape.

[AJAXJR24]

dear @lululxvi Thanks for your reply Would these vertices be problematic if the heat equation is solved in a rectangular domain in which 2 of the adjacent sides are RobinBC and the other 2 are NeumannBC?

[lululxvi]

Theoretically, it could cause some problem, but in practice, sometimes it is fine.