4 ms·
This technique should be straightforwardly adaptable to compute arbitrary moments, not just the centroid. If you have a scalar-valued function that you can con
by amluto 1mo ago
This technique should be straightforwardly adaptable to compute arbitrary moments, not just the centroid.
If you have a scalar-valued function that you can conveniently express as the divergence of any closed-form function, you can integrate it like this. And you can generalize beyond scalar-valued functions and beyond Euclidean space using the generalized Stokes’ theorem.
You can even do this in real life: if you want to integrate the electric current density through a surface (that is, measure the total current crossing the surface), you can integrate its anti-curl (is that a word?) around the boundary of that surface, which is what a current transformer or a clamp-on current meter does.
I bet there’s a hydraulic or pneumatic analog as well, but a nontrivial example isn’t immediately coming to mind.
- ted_dunning 1mo agoThe hydraulic analog is that you can weigh a volume of water (which is the same as computing its volume) by adding up the forces on the surface surrounding the water. This looks like it requires a dot product with the normal vector for each triangle, but you can expand it into the same form as the article.