Thank you for the answer. It is a pity, that I cannot obtain unitary matrix from the set of orthogonal columns. I must think of another method.
Regards, Marek 13-05-2016 18:08 użytkownik "Alexander Hulpke" <hul...@fastmail.fm> napisał: > Dear Forum, Dear Marek Mitros, > > Sqrt (as a short hand for the ER cyclotomic) will only work for rational > numbers. If you wanted a square root of a cyclotomic number you would need > to factor x^2-a over a suitable cyclotomic field. > > Best, > > Alexander Hulpke > > > On May 13, 2016, at 8:30 AM, Marek Mitros <ma...@mitros.org> wrote: > > > > Dear All, > > > > I am doing following calculation and I need square root of cyclotomic > > number being real number. Here is example below. Is there any workaround > > for this ? > > What I am doing I obtained vector v of complex number which not unit > > length. In order to normalize it I perform following and I receive the > > error. Do I need more knowledge about cyclotomic numbers ? > > > > gap> v1:=v/Sqrt(v*ComplexConjugate(v)); > > > > Error, no method found! For debugging hints type ?Recovery from > > NoMethodFound > > > > Error, no 1st choice method found for `Sqrt' on 1 arguments called from > > > > <function "HANDLE_METHOD_NOT_FOUND">( <arguments> ) > > > > (...) > > > > gap> n:=E(20)-E(20)^9; > > > > E(20)-E(20)^9 > > > > gap> RealPart(n); > > > > E(20)-E(20)^9 > > > > gap> Sqrt(n); > > > > Error, no method found! For debugging hints type ?Recovery from > > NoMethodFound > > > > Error, no 1st choice method found for `Sqrt' on 1 arguments called from > > > > > > Regards, > > > > Marek > > _______________________________________________ > > Forum mailing list > > Forum@mail.gap-system.org > > http://mail.gap-system.org/mailman/listinfo/forum > > _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
