I’m playing with my own PGA implementation, and I’m getting some confusing results trying to debug basic parts. Most critical seems to be the dual operator. The python and cpp code generated by the site flips the order of the multi vector coefficients, and uses the same basis order as the PGA cheat sheet. The Expression Evaluator seems to use something different, producing sign changes in grade 1 elements:
!(1+e0+e1+e2+e3+e01+e02+e03+e12+e31+e23+e021+e013+e032+e123+e0123) = 1-e0-e1-e2-e3+e01+e02+e03+e12-e13+e23-e012+e013-e023+e123+e0123
The different basis elements in the output suggest the evaluator is using e13 instead of e31, for example, but I still can’t quite reconcile that with all the grade 1 sign changes. Perhaps I should be requesting a way to control the basis element set/order.