Outward pointing normal vectors on a triangle

Hey guys.

I'm using the Galerkin method to solve a heat convection problem in 2d.

I have a triangle and I've found the normal vectors to the triangle side.

%Length of one side: a1 = sqrt((x3-x2)^2+(y3-y2)^2);

%Normal vector: n1 = [(x3-x2),y3-y2]./a1;

The problem is that I don't know how to make matlab make the normal vectors point outwards automatically.

So if anyone has a suggestion please tell me.

thanks, Kjartan

Answer 1

[Brett Shoelson]

Are you familiar with the QUIVER command?

Brett