[GAP Forum] Converting a permutation to a list

[Tim Kohl]

gap> allsupports:=function(perm,n) return(Filtered(Cycles(perm,[1..n]),x->Size(x)>1));end;

gap> allsupports((1,2,3)(5,6),6);
[ [ 1, 2, 3 ], [ 5, 6 ] ]

	-T


On Mon, 18 Aug 2014, Pierre-Alain BOURDIL wrote:

> Greetings,
> 
> i'm looking for a function , say F, such that
> 
>  F((1,2,3)(5,6)) = [[1,2,3],[5,6]].
> 
> My goal is to use the output list as index to fetch string from a separate
> list (eg: ["a","b","c","d","e"]). I need to express permutation  on the latter
> (eg: ("a","b","c")("d","e")) ) , do some computation using gap permutation
> group, and  convert back the output of gap to permutation of these strings.
> 
> I've seen PermList and ListPerm but it's not a cyclic notation. There's
> possibly better way to make a permutation acting on an ordred set of string
> but my point is the input/output with gap.
> 
> 

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Dr. Timothy Kohl | Desktop Services Specialist, Sr.
Boston University| IT Help Center | IS&T
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