Paul Zinn-Justin
Paul Zinn-Justin
actually, it seems strategy 3 of `minimalPresentation` (modules2.m2 L207) already implements pretty much what you suggest.
one thing I can never figure up working with modules: When one defines a module `M` as an image, how can one easily access the embedding map from `M` to...
maybe this could just replace the current "Inhomogeneous" strategy? which doesn't do much anyway. edit: oh, is that strategy ever called anyway? `help Inhomogeneous` suggests that for gb computations this...
I'll look into the `prune` bug you found
I suspect `smithNormalForm`. in particular, the fact that it gives different results depending on the option `ChangeMatrix` is highly suspicious, but the documentation is not very clear on that.
There seem to be at least two distinct issues: ``` i1 : R=QQ[x] o1 = R o1 : PolynomialRing i2 : f=random(R^{1,2,3,4},R^{0,1}) o2 = {-1} | 7x 1 | {-2}...
Fatal bug: ``` i1 : R=QQ[x] o1 = R o1 : PolynomialRing i2 : smithNormalForm matrix{{x^3+2},{x^3+x^2}} o2 = (| 2 |, | x2+1 -x2+x-2 |, {3} | 1 |) |...
I don't know how to fix the `smithNormalForm` bug, I made a separate issue. The best I could come up with is a one-line workaround so that `prune` works normally:...
that being said, this whole `prune` hook should probably be reviewed once `smithNormalForm` is fixed, since it's clearly out of sync with the code of the latter -- for example...
can finally be closed!