Thanks Stefan. Let me ask a stupid question based on my one day of experience in Julia: Why does the compiler not understand that a negative power will always result in numbers requiring floating point precision? My guess is that it has to do with the type inference mechanism. But exactly what it is?
I see John wrote about the type instability and speed of execution in http://www.johnmyleswhite.com/notebook/2013/12/06/writing-type-stable-code-in-julia/ Is there a trick which will force the compiler to consider all variables and function arguments, local or not, to be of certain type unless explicitly overridden? I ask this question since I would think that while doing scientific computation a user will mostly use one numeric type. Is this a terrible idea? On Friday, 6 June 2014 22:18:59 UTC-4, Stefan Karpinski wrote: > > A perennial struggle. In this case I personally didn't take it in a bad > way – I can certainly see how it seems stupid unless you know about the > type stability issue. This is one of those unsatisfying corners of reality > that don't seem to have a satisfying solution. > > On Jun 6, 2014, at 9:56 PM, John Myles White <[email protected] > <javascript:>> wrote: > > No worries. After more than two years on it, I’m still figuring out what’s > the right tone for the mailing list. > > — John > > On Jun 6, 2014, at 6:42 PM, Zahirul ALAM <[email protected] > <javascript:>> wrote: > > Thanks John. > > with regards to your side note, I will refrain from using that word. In my > defense, my drink-fuddled brain was very frustrated. ;) > > On Friday, 6 June 2014 20:10:14 UTC-4, John Myles White wrote: >> >> You should use 10^-2.0. The way you’re trying to do things would require >> that the power function produce different types of outputs for different >> input values, which would make optimization/compilation difficult. >> >> As a side note, I think you’ll find it’s more effective not to use the >> word “stupid”. >> >> — John >> >> On Jun 6, 2014, at 5:05 PM, Zahirul ALAM <[email protected]> wrote: >> >> > 10^2 returns 100; >> > but 10^-2 or 10^(-2) returns ERROR: DomainError in power_by_squaring >> at intfuncs.jl:60 in ^ at intfuncs.jl:84 >> > >> > do I have to use 1/10^2 instead? >> > >> > This seems rather stupid. is it a Bug? I am using the nightly build >> version downloaded a couple of days ago. I am new to Julia and trying to >> convert my a large Mathematica code in Julia. >> >> >
