Hi, I wonder how I could compare real numbers in GAP i.e. cyclotomics which are real. I try Float but it doesn't work for cyclotomics - any advice ? Say my numbers are limited to CF(5) field. Here is example: sigma:=(E(5)+E(5)^4)/2; # = RealPart(E(5)) = (Sqrt(5)-1)/4 = 0.309... is real number. How I can compare whether it is bigger or smaller that 1/2 ? It is known that this number is equal to Another real number in CF(5) is tau:=-RealPart(E(5)^2); # =-(E(5)^2+E(5)^3)/2=(Sqrt(5)+1)/4 = 0.809...=sigma+1/2
How could I develop function comparing elements of the field generated by sigma and tau ? I mean comparison as real numbers. I can obtain coefficients for given number x: Coefficients(Basis(Field(sigma)), x) Using this can I find the position of the number on real axis ? I.e. compare with another field element or rational number ? I would really be nice to have possibility of comparing real subset of cyclotomics are real numbers in GAP. Regards, Marek _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
