Re: [sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-06-06 Thread Dima Pasechnik
On Thu, 6 Jun 2019 15:08 Michael Jung, wrote: > How can I delete the actual branch on trac and create a new one? > this can be done with the usual git commands - google for git delete remote branch > And: How do I merge properly to the recent beta version? > a proper way would be to do git

[sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-06-06 Thread Michael Jung
How can I delete the actual branch on trac and create a new one? And: How do I merge properly to the recent beta version? I am sorry, it seems I'm too stupid for git trac. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this

Re: [sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-05-18 Thread Michael Jung
Damn it, I feel so stupid! :D Thanks, this did the job. :) Am 15.05.2019 um 14:48 schrieb Travis Scrimshaw: However, the interesting part for me is the commutative subalgebra of even mixed forms which I could certainly implement. But I am not sure whether this will work due to the

[sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-05-15 Thread Travis Scrimshaw
> > > However, the interesting part for me is the commutative subalgebra of even > mixed forms which I could certainly implement. But I am not sure whether > this will work due to the error message above... > The error message indicates what you need to do: implement an is_field() method that

[sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-05-15 Thread Michael Jung
Actually, I get the error: --- AttributeErrorTraceback (most recent call last) in () > 1 det = matrix.determinant(); show(det)

[sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-05-14 Thread Travis Scrimshaw
I think a lot of the matrix code is assumed to work over commutative rings, but there is no assumption on them being fields. The MixedFormAlgebra is not commutative, correct? If so, I think the best thing is to implement what you need (i.e., the determinant) as a separate function for now.

[sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-05-14 Thread Michael Jung
Unfortunately, I noticed that the algorithm of computing the determinant of MixedForm elements doesn't work for matrices of dimension higher than 3 since MixedFormAlgebra isin general not a field. So, is it useful to create a new matrix class for this kind of purpose? If so, how is the matrix

Re: [sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-05-03 Thread Michael Jung
Hello, Having vector bundles would be nice! But what do you mean by *abstract* vector bundle? Ah. I meant vector bundles without specifying any maps. But since changes of frames/coordinates and continuations are convenient to have, this seems unavoidable. Where would you start if you'd program

[sage-devel] Re: Characteristic Classes - Implement Vector Bundles?

2019-05-03 Thread Eric Gourgoulhon
Hi, Le jeudi 2 mai 2019 13:12:43 UTC+2, Michael Jung a écrit : > > Hey there, > for the next step of implementing characteristic classes, I'd like to > implement abstract vector bundles. > > 1) Do you agree? > Having vector bundles would be nice! But what do you mean by *abstract* vector