If b is rational then a^b is irrational in general, even for a integer, so this output is quite expected, as well as
julia> (10//1)^(2//1) 100.0 Le lundi 9 juin 2014 00:54:37 UTC+2, Miguel Bazdresch a écrit : > > I just tried this (on 0.2.1): > > julia> (10//1)^(-2//1) > 0.01 > > Is this expected? > > -- mb > > > > On Sun, Jun 8, 2014 at 6:36 PM, 'Stéphane Laurent' via julia-users < > julia...@googlegroups.com <javascript:>> wrote: > >> julia> (10//1)^(-2) >> >> 1//100 >> >> >> Would it be problematic to return a rational >> for (a::Integer)^(b::Integer) ? >> >> >> >> Le dimanche 8 juin 2014 21:53:45 UTC+2, Stefan Karpinski a écrit : >>> >>> There are three obvious options for (a::Integer)^(b::Integer): >>> >>> 1. Always return an integer ⟹ fails for negative b. >>> 2. Always return a float ⟹ a^2 is not the same as a*a. >>> 3. Return float for negative b, integer otherwise ⟹ not type-stable. >>> >>> As you can see, all of these choices are problematic. The first one, >>> which is what we currently do, seems to be the least problematic. One >>> somewhat crazier option that has been proposed is making ^- as in a^-b >>> parse as a different operator and have a^b return an integer for integer >>> arguments but a^-b return a float for integer arguments. This would have >>> the unfortunate effect of making a^-b different from a^(-b). >>> >>> >>> On Sat, Jun 7, 2014 at 12:41 PM, Daniel Jones <daniel...@gmail.com> >>> wrote: >>> >>>> I'd definitely be in favor of '^' converting to float, like '/', >>>> having fallen for than recently >>>> <https://github.com/JuliaLang/Color.jl/commit/c3d05dd2b94f0d38b64ef86022accdfec886a673> >>>> . >>>> >>>> On Sat, Jun 7, 2014, at 12:53 AM, Ivar Nesje wrote: >>>> > >>>> > There has also been discussion on whether ^(a::Integer,b::Integer) >>>> should >>>> > return a Float64 by default, and defer to pow() like /(a::Integer, >>>> > b::Integer) defers to div(). The problem is that many people like the >>>> > 10^45 vs 1e45 notation for large integers vs float constants, and we >>>> can >>>> > make it a clean error instead of a silent bug. >>>> >>>> >>> >>> >
