Action for Bundle Connections

[gh-mjungmath]

In this ticket, we establish the action of a bundle connection. We implement the component-wise formula based on the connection form.

See ​Wikipedia for details.

[gh-mjungmath]

Last 10 new commits:

​f0c6ee8	Trac #30191: minor fix
​f1221da	Trac #30191: minor fix
​a042313	Trac# 30191: wrong indentation reverted
​4cc92e9	Trac #30191: comp check unified to if comp
​f98a47b	Trac #30191: unused ScalarField import removed
​9c5a25b	Trac #30208: assigment for bundle connections
​fa87f4b	Trac #30208: documentation improved
​b7a6a5f	Merge branch 'develop' into bundle_connection_change_of_frame
​0c28d89	Trac #30209: forms from scratch
​56996fd	Trac #30209: bundle connection action

[git]

Branch pushed to git repo; I updated commit sha1. Last 10 new commits:

​ef8ac4b	Trac #30209: display method + merge
​51ba4e3	Trac #30239: comp zero check for __call__
​bd1f299	Trac #30209: Merge branch 't/30239/tensorfield___call___alters_zero' into bundle_connection_change_of_frame
​e7fedb7	Trac #30209: display method finished
​b03baa1	Trac #30209: structure formula fixed
​bb476e2	Trac #30208: minor fix
​a77aebc	Trac #30208: copy_from reverted to recover old behavior
​934a439	documentation slightly improved
​574445d	Trac #30209: Merge branch 'bundle_connection_extension' into bundle_connection_change_of_frame
​0e3cba0	Trac #30209: documentation finished + display only_nonzero fixed

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​2dd78aa

Trac #30209: documentation improved

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​e5a3ac4

Trac #30209: documentation imrpoved

[gh-mjungmath]

I don't think the depencency of #30239 is necessary anymore. Anyway, I'll leave it this way. Removing it again would be too complicated by now...

[gh-mjungmath]

The pycodestyle error has been fixed in #30239.

[git]

Branch pushed to git repo; I updated commit sha1. Last 10 new commits:

​504e84e	Trac #30239: Merge branch 't/30266/immutability_for_scalar_fields' into t/30239/tensorfield___call___alters_zero
​d58d291	Trac #30266: hash function condition + treatment of restrictions
​061b89f	Trac #30266: minor doctest improvement
​5c7fd6e	Trac #30266: immutability of restrictions + hash function improved
​7ba0865	Trac #30266: merge
​0ec99d4	Trac #30266: check by name
​87fb411	Trac #30266: ValueError replaced by AssertionError
​43ec497	Trac #30239: referenced before assignment error fixed
​135ffd5	Trac #30209: Merge branch 't/30239/tensorfield___call___alters_zero' into bundle_connection_change_of_frame
​933c14a	Trac #30209: Merge branch 'develop' into bundle_connection_change_of_frame

[git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

​d3c8cab	Trac #30208: random doctest removed
​5cee80c	Trac #30209: Merge branch 'bundle_connection_extension' into bundle_connection_action
​21f2bd5	Trac #30209: bundle connections acting on sections + vector fields

[gh-mjungmath]

I have removed the dependency of #30239.

[gh-mjungmath]

Green patchbot.

[tscrim]

I don't like doctests marked as random that are not random:

sage: nab.connection_forms() # random

Just go through the different values and get the output explicitly (and maybe check the len). This will be more robust and actually catch errors.

Your error messages in display don't need to be so excited (just remove the ! from the end).

While it is good to keep encapsulation, just be aware that changes like this:

-                    rk = vb._rank
+                    rk = vb.rank()

mean extra Python function calls, which are relatively expensive compared to attribute lookup. However, I have no objections to these changes as they seem like they would not have any significant impact on computation times.

[gh-mjungmath]

Replying to tscrim:

I don't like doctests marked as random that are not random:

sage: nab.connection_forms() # random

Just go through the different values and get the output explicitly (and maybe check the len). This will be more robust and actually catch errors.

Ah, you already mentioned that in some ticket. Sure, I will take care of that.

Your error messages in display don't need to be so excited (just remove the ! from the end).

:(

While it is good to keep encapsulation, just be aware that changes like this:

-                    rk = vb._rank
+                    rk = vb.rank()

mean extra Python function calls, which are relatively expensive compared to attribute lookup. However, I have no objections to these changes as they seem like they would not have any significant impact on computation times.

Ah, this is good to know! I'll change it back.

Tomorrow...

[git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

​ec05c7f	Trac #30209: Merge branch 't/30208/d3c8cab917f04ebc9951d41a0cc8dcf4c66392a6' into new_bundle_connection_action
​7ae2df9	Trac #30209: action of bundle connections + display method

[gh-mjungmath]

I see. Something went wrong during the rebase. Please double check in comparison with #30208.

[gh-mjungmath]

I've forced a new push btw. Like I said, please take a thorough look.

[gh-mjungmath]

Compared with #30208 once again. Looks good, like intended. Patchbot is green again.

[tscrim]

Thank you. LGTM.

[gh-mjungmath]

Thank you for the review.