Dear GAP Forum,
Stas Bulygin wrote:
>
> Dear GAP-Forum,
> I got the following problem in package GUAVA 1.4:
> gap> GeneratorMat(HammingCode(3,GF(2)));
> [ <an immutable GF2 vector of length 7>, <an immutable GF2 vector of length
> 7>
> , <an immutable GF2 vector of length 7>,
> <an immutable GF2 vector of length 7> ]
>
> What should I do to obtain the generator matrix in the explicit form, or how
> should I read this output?
The following should work.
gap> RequirePackage("guava"); gap> G:=GeneratorMat(HammingCode(3,GF(2))); [ <an immutable GF2 vector of length 7>, <an immutable GF2 vector of length 7> , <an immutable GF2 vector of length 7>, <an immutable GF2 vector of length 7> ] gap> GM:=[]; [ ] gap> for j in [1..4] do > GM[j]:=List([1..7],i->G[j][i]); > od; gap> GM; [ [ Z(2)^0, Z(2)^0, Z(2)^0, 0*Z(2), 0*Z(2), 0*Z(2), 0*Z(2) ], [ Z(2)^0, 0*Z(2), 0*Z(2), Z(2)^0, Z(2)^0, 0*Z(2), 0*Z(2) ], [ 0*Z(2), Z(2)^0, 0*Z(2), Z(2)^0, 0*Z(2), Z(2)^0, 0*Z(2) ], [ Z(2)^0, Z(2)^0, 0*Z(2), Z(2)^0, 0*Z(2), 0*Z(2), Z(2)^0 ] ]
Hope that helps. - David
--
Prof David Joyner, Mathematics Department
U. S. Naval Academy, Annapolis, MD 21402
phone: (410) 293-6738