Dear Stephen Linton, Thank you very much for your help.
> Performance is one consideration, of course. Another is making use of already > computing information about the group when possible. Still another is > computing > data structures that are likely to be useful for further computations. The > GAP > library function, having found a group to be solvable will also have > constructed > a data structure called a Pcgs (PolyCyclic Generating System) which can be > used > to greatly speed up many further computations with the group. I am interesting in "PolyCyclic Generating System". So I'll try to read the source . Although it is doubtful whether I can do understand it. What you have told me is , seems to me to lower the difficulty of reading the source . Thank you very much for letting me know clearly the point and Pcgs. With best regards buynnnmmm1 ----- Original Message ----- > From: Stephen Linton <steve.lin...@st-andrews.ac.uk> > To: buynnnm...@yahoo.co.jp > Cc: Alexander Konovalov <al...@mcs.st-andrews.ac.uk>; GAP Forum > <fo...@gap-system.org> > Date: 2014/9/17, Wed 22:18 > Subject: Re: [GAP Forum] Is it possible to step through the program, like GNU > GDB debugger, against built-in functions(ex. DerivedSubgroup, > ClosureSubgroupNC )? > > > On 17 Sep 2014, at 13:57, buynnnm...@yahoo.co.jp wrote: >> >> myIsSolvable:=function ( x ) >> local d; >> d := DerivedSeries( x ); >> return IsTrivial( d[Size( d )] ); >> end >> >> >> gap> List([1..30], x -> myIsSolvable(SymmetricGroup(x))) = > List([1..30], x -> IsSolvable(SymmetricGroup(x))); >> true >> >> For Symmetric Group, the same results have been obtained. >> So I'm going to try to do withmyIsSolvable function that uses the > DerivedSeries function. >> >> There was a difference of more than twice the run time to IsSolvable of > built-in and myIsSolvable Taking the profile. >> >> Built-in IsSolved Would has become the source code I hard to understand in > order to increase the execution speed? >> > > > Performance is one consideration, of course. Another is making use of already > computing information about the group when possible. Still another is > computing > data structures that are likely to be useful for further computations. The > GAP > library function, having found a group to be solvable will also have > constructed > a data structure called a Pcgs (PolyCyclic Generating System) which can be > used > to greatly speed up many further computations with the group. > > Steve > _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
