Opened 5 years ago
Closed 5 years ago
#18774 closed enhancement (fixed)
Janko Groups and Livingstone graph
Reported by:  ncohen  Owned by:  

Priority:  major  Milestone:  sage6.8 
Component:  group theory  Keywords:  
Cc:  dimpase, vdelecroix  Merged in:  
Authors:  Nathann Cohen  Reviewers:  Dima Pasechnik 
Report Upstream:  N/A  Work issues:  
Branch:  d07e879 (Commits)  Commit:  d07e879d167c82d8f304b055ee290c67e57374e0 
Dependencies:  Stopgaps: 
Description
This branch exposes the Janko groups from gap, and builds the Livingstone Graph from J1
https://en.wikipedia.org/wiki/Janko_group https://en.wikipedia.org/wiki/Livingstone_graph
Nathann
Change History (28)
comment:1 Changed 5 years ago by
 Branch set to public/18774
 Cc vdelecroix added
 Commit set to 42e61b8290df7dd67a5a0e14c6f9101750f249bc
 Status changed from new to needs_review
comment:2 Changed 5 years ago by
 Commit changed from 42e61b8290df7dd67a5a0e14c6f9101750f249bc to 8b7160a453bbd24d5e684f9577115ad963188ef6
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
8b7160a  trac #18774: Livingstone Graph and Janko Groups

comment:3 followup: ↓ 5 Changed 5 years ago by
 Status changed from needs_review to needs_work
JankoGroup(4)
should throw NotImplementedError
; I don't think anyone wants a permutation
group of degree 173067389, and they aren't known by AtlasRep
, as far as I know (IMHO
they have the same data as in http://brauer.maths.qmul.ac.uk/Atlas/v3/spor/J4/).
gap> i:=AtlasGroup("J4"); <matrix group of size 86775571046077562880 with 2 generators>
while for the remaining values of k<4 you get
gap> i:=AtlasGroup("Jk"); <permutation group of size ....... with 2 generators>
comment:4 Changed 5 years ago by
 Commit changed from 8b7160a453bbd24d5e684f9577115ad963188ef6 to 7efe54b39c46a81ce862fc5e395db3a456127b43
Branch pushed to git repo; I updated commit sha1. New commits:
7efe54b  trac #18774: no J4

comment:5 in reply to: ↑ 3 Changed 5 years ago by
 Status changed from needs_work to needs_review
Hello,
JankoGroup(4)
should throwNotImplementedError
;
Right, right. I simplified it and requested an integer from 1 to 3 instead.
Nathann
comment:6 followup: ↓ 7 Changed 5 years ago by
 Status changed from needs_review to needs_work
tests do not pass
shouldn't this be tagged optional  gap_something ?
comment:7 in reply to: ↑ 6 Changed 5 years ago by
shouldn't this be tagged optional  gap_something ?
HMmm... Gap isn't optional. And with gap installed on my computer, I did not notice that an optional package was needed ^^;
I don't even know which package is needed O_o
Nathann
comment:8 followup: ↓ 9 Changed 5 years ago by
comment:9 in reply to: ↑ 8 Changed 5 years ago by
comment:10 Changed 5 years ago by
 Commit changed from 7efe54b39c46a81ce862fc5e395db3a456127b43 to 93801c8bd1834243c34eed3bc78b0113c26439b1
Branch pushed to git repo; I updated commit sha1. New commits:
93801c8  trac #18774: optional gap packages

comment:11 followup: ↓ 12 Changed 5 years ago by
 Status changed from needs_work to needs_review
It works offline, but gap_packages must be installed.
comment:12 in reply to: ↑ 11 ; followup: ↓ 13 Changed 5 years ago by
Replying to ncohen:
It works offline,
Really? http://www.math.rwthaachen.de/~Thomas.Breuer/atlasrep/ (the official wwwpages of the package) says
Note that the package archives do NOT contain the database part of the package; the GAP interface accesses the data on demand via the internet.
comment:13 in reply to: ↑ 12 ; followup: ↓ 14 Changed 5 years ago by
Really?
I built if offline. You think that they have a caching mechanism for that, between sessions?...
Nathann
comment:14 in reply to: ↑ 13 Changed 5 years ago by
Replying to ncohen:
Really?
I built if offline. You think that they have a caching mechanism for that, between sessions?...
of course you can build
it offline, but not use
offline
(although perhaps some of its data is in other GAP databases).
perhaps one has to read its code...
Nathann
comment:15 Changed 5 years ago by
TFM says:
4.3 User Parameters for the AtlasRep Package This section lists global parameters for which it might make sense to change their defaults by assignments to global variables, either just for the current GAP session or as user preferences in the user's gaprc file (see Reference: The gap.ini and gaprc files). For an overview of these parameters, see AtlasOfGroupRepresentationsUserParameters (4.38). 4.31 Local or Remote Access There are two possibilities to use the AtlasRep package. Local access only (offline) You can restrict the access to the data that are actually stored in the local installation of GAP. Remote access (online) If your computer is connected to a network that provides access to the ATLAS data (for example the internet) then the functions of the package may fetch the requested data automatically from remote servers when they are required for the first time; these data are then by default stored in the local copy, so later access to them needs no network transfer. The latter possibility is presently not used by other GAP packages, so it may be regarded as an important feature of the AtlasRep package. Anyhow it requires a few words of explanation. ...
comment:16 followup: ↓ 17 Changed 5 years ago by
I just did the following:
 Went offline
 'sage f gap_packages'
 'rm rf ~/.sage/gap/'
 'make'
 'sage br'
sage: graphs.LivingstoneGraph() Livingstone Graph: Graph on 266 vertices
So for the moment, I will keep on believing that this works offline. Unless you know where it could be cached?
Nathann
comment:17 in reply to: ↑ 16 ; followup: ↓ 18 Changed 5 years ago by
Replying to ncohen:
So for the moment, I will keep on believing that this works offline. Unless you know where it could be cached?
RTFM?
Then, there is stuff in $SAGE_LOCAL/gap
comment:18 in reply to: ↑ 17 ; followups: ↓ 21 ↓ 25 Changed 5 years ago by
RTFM?
Always a pleasure to work with you dima.
Then, there is stuff in
$SAGE_LOCAL/gap
Yeah, I just figured this out offline. The thing is that you are not supposed to have writing access to SAGE_LOCAL/gap, so that's not precisely where cached information should be stored. It should be done in ~/.sage/gap
Anyway, this requires internet indeed.
Nathann
comment:19 Changed 5 years ago by
 Commit changed from 93801c8bd1834243c34eed3bc78b0113c26439b1 to 2548e0e0802bb6ee504c87f7a03608b070c1c88c
Branch pushed to git repo; I updated commit sha1. New commits:
2548e0e  trac #18774: internet

comment:20 Changed 5 years ago by
 Commit changed from 2548e0e0802bb6ee504c87f7a03608b070c1c88c to e977c1769111993bf016d46f0aa236ca43d9ea74
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
e977c17  trac #18774: internet

comment:21 in reply to: ↑ 18 ; followup: ↓ 22 Changed 5 years ago by
Replying to ncohen:
RTFM?
Always a pleasure to work with you dima
as we know, it's just an abbreviation of "Highly respected colleague, allow me most humbly point to availability of material that might alleviate doubts you have hinted at in your most valuable comments above"
:)
comment:22 in reply to: ↑ 21 Changed 5 years ago by
as we know, it's just an abbreviation of [...]
I see. My life so far has been a lie.
Nathann
comment:23 Changed 5 years ago by
 Commit changed from e977c1769111993bf016d46f0aa236ca43d9ea74 to d07e879d167c82d8f304b055ee290c67e57374e0
Branch pushed to git repo; I updated commit sha1. New commits:
d07e879  say why J4 is not there

comment:24 Changed 5 years ago by
Nathann, LGTM. Feel free to flip it to positive review if you're happy with my last commit.
comment:25 in reply to: ↑ 18 ; followup: ↓ 26 Changed 5 years ago by
Replying to ncohen:
Then, there is stuff in
$SAGE_LOCAL/gap
Yeah, I just figured this out offline. The thing is that you are not supposed to have writing access to SAGE_LOCAL/gap, so no information should be cached there. It should be done in
~/.sage/gap
so is there (where?) a bug?
comment:26 in reply to: ↑ 25 Changed 5 years ago by
so is there (where?) a bug?
Not sure. They may write to the systemwide repository if they can, and if they cannot then they write to the home gap directory.
comment:27 Changed 5 years ago by
 Reviewers set to Dima Pasechnik
 Status changed from needs_review to positive_review
LGTM. Feel free to flip it to positive review if you're happy with my last commit.
Works for me. Thanks!
Nathann
comment:28 Changed 5 years ago by
 Branch changed from public/18774 to d07e879d167c82d8f304b055ee290c67e57374e0
 Resolution set to fixed
 Status changed from positive_review to closed
New commits:
trac #18774: Livingstone Graph and Janko Groups