[GAP Forum] how to recognise a group?

[R.E. Boss]

Thanks all for your help. 
It took some time to fiddle out the directories, but now GAP is crunching on the multiplication table.


R.E. Boss


> -----Oorspronkelijk bericht-----
> Van: rfmorse at gmail.com [mailto:rfmorse at gmail.com] Namens Robert Morse
> Verzonden: vrijdag 17 augustus 2012 16:38
> Aan: R.E. Boss
> CC: forum at gap-system.org
> Onderwerp: Re: [GAP Forum] how to recognise a group?
> 
> You can create a file with GAP commands and read them into GAP with
> the Read command.
> 
> If you put
> 
> M := [ [ 1, 2, 3, 4, 5 ], [ 2, 3, 4, 5, 1 ], [ 3, 4, 5, 1, 2 ], [ 4,
> 5, 1, 2, 3 ], [ 5, 1, 2, 3, 4 ] ];
> 
> in a file "table.g" and at the GAP command prompt
> 
> gap> Read("table.g");
> gap> M;
> [ [ 1, 2, 3, 4, 5 ], [ 2, 3, 4, 5, 1 ], [ 3, 4, 5, 1, 2 ], [ 4, 5, 1,
> 2, 3 ], [ 5, 1, 2, 3, 4 ] ]
> 
> you see the variable is assigned as needed.
> 
> I am assuming that you are generating the tables using some program.
> If so make sure it is formatted as a list of lists that GAP can use.
> 
> Also look at
> 
> http://www.gap-system.org/Manuals/doc/ref/chap9.html#X8373AC6B7D5F9167
> 
> for more information on the GAP read command.
> 
> Robert
> 
> On Fri, Aug 17, 2012 at 8:56 AM, R.E. Boss <r.e.boss at planet.nl> wrote:
> > Thanks for the reply.
> > Problem becomes: how do I enter a multiplication table of 2304 = 48^2 elements into GAP?
> > Is there some read facility?
> > Preparing a list of 48 lists of 48 elements is not the problem, entering by hand is quite another story.
> >
> >
> > R.E. Boss
> >
> >
> >> -----Oorspronkelijk bericht-----
> >> Van: rfmorse at gmail.com [mailto:rfmorse at gmail.com] Namens Robert Morse
> >> Verzonden: donderdag 16 augustus 2012 14:51
> >> Aan: R.E. Boss
> >> CC: forum at gap-system.org
> >> Onderwerp: Re: [GAP Forum] how to recognise a group?
> >>
> >> In my example the table M is the cyclic group.
> >>
> >> Given the multiplication table say M do the following:
> >>
> >> Form the group using the multiplication table:
> >>
> >> gap> G := GroupByMultiplicationTable(M);
> >> <group of size 48 with 48 generators>
> >>
> >> Ask for some structural information to get an idea what the group is:
> >>
> >> gap> StructureDescription(G);
> >> "C48"
> >>
> >> Robert F. Morse
> >>
> >> On Tue, Aug 14, 2012 at 1:49 PM, R.E. Boss <r.e.boss at planet.nl> wrote:
> >> > Hello,
> >> >
> >> >
> >> >
> >> > I'm new to Gap and using it for a couple of days only and would like to have the next question answered.
> >> >
> >> > If I have a multiplication table of a (small) group, how can I determine which group it is?
> >> >
> >> > The actual table I have is for group of 48 elements.
> >> >
> >> >
> >> >
> >> > R.E. Boss
> >> >
> >> >
> >> >
> >> >
> >> >
> >> > _______________________________________________
> >> > Forum mailing list
> >> > Forum at mail.gap-system.org
> >> > http://mail.gap-system.org/mailman/listinfo/forum
> >