Recog An/Sn unknown degree: conder, holt

[ssiccha]

A PR based on #176.

We are going to implement the extensions by Conder and Derek Holt's
GuessAltSymDegree.

[ssiccha]

Rebased the last commit onto the current version of #176.

[codecov]

Codecov Report

Merging #265 (fe2066e) into master (628f227) will decrease coverage by 0.57%.
The diff coverage is 100.00%.

❗ Current head fe2066e differs from pull request most recent head deb2974. Consider uploading reports for the commit deb2974 to get more accurate results

@@            Coverage Diff             @@
##           master     #265      +/-   ##
==========================================
- Coverage   78.59%   78.01%   -0.58%     
==========================================
  Files          43       43              
  Lines       18459    18520      +61     
==========================================
- Hits        14508    14449      -59     
- Misses       3951     4071     +120     

Impacted Files	Coverage Δ
gap/generic/SnAnUnknownDegree.gi	98.26% <100.00%> (+0.51%)	⬆️
gap/projective/AnSnOnFDPM.gi	77.62% <0.00%> (-12.14%)	⬇️
gap/perm/giant.gi	89.68% <0.00%> (-3.59%)	⬇️
gap/matrix/matimpr.gi	69.03% <0.00%> (-3.23%)	⬇️
gap/projective/classicalnatural.gi	92.57% <0.00%> (-1.61%)	⬇️
gap/projective/almostsimple.gi	65.64% <0.00%> (-0.20%)	⬇️
gap/base/recognition.gi	68.79% <0.00%> (-0.13%)	⬇️
gap/projective/c3c5.gi	87.86% <0.00%> (-0.03%)	⬇️
gap/matrix.gi	94.40% <0.00%> (-0.03%)	⬇️
gap/perm.gi	97.27% <0.00%> (-0.02%)	⬇️
... and 9 more

[FriedrichRober]

Link to our Hackmd

[ssiccha]

We should be almost done. We think there are two TODOs left: clean up the tests and figure out what to do with small classical groups like: Omega(-1,4,3). It has element orders <= 5, thus slips through our heuristics to weed out groups which are not isomorphic to An or Sn. Hence the SnAnUnknownDegree algorithm takes forever until it realizes, that the group in question is not an An or Sn. We think we should be able to alleviate this by simply saying that we're NeverApplicable if the vector space our group acts has less than e.g. 100 elements. And then we'll post a challenge on slack or the GAP forum whether somebody can find a small group, which makes the algorithm run slow.

And get the tests to pass again. :)

And in Make CallMethods directly write into the RecogNode update the docs of CallMethods.

And, @FriedrichRober is writing a short text, how all the parts fit together, that is how our implementation differs from a "vanilla" implementation of the JLNP algorithm according to the paper.

[fingolfin]

Awesome, thank you!

[fingolfin]

@FriedrichRober do you think you can finish this on your own, now that @ssiccha is gone? Perhaps I can help a bit?

[FriedrichRober]

Yes, I think I can finish this on my own. The code is finished (except for handling small classical groups). What is missing now is to finish the documentation (comments) and looking at the runtime of the test suite.

[FriedrichRober]

@fingolfin, ich habe nun die Änderungen implementiert, wie wir es besprochen haben. Wir geben früher auf, und speichern uns die Iteratoren im recog node ab, um sie später weiter zu verwenden. Trotzdem dauert die Test-Suite auf meinem Rechner 3-4 Minuten länger als auf dem master. Meiner Meinung nach ist dieser Zustand inakzeptabel, um das einfach so zu mergen :(

Ich muss dann nochmal genau schauen, an welchen Stellen wir zu viel Zeit verschwenden, und ob sich da was machen lässt.