From: jzakiya on 7 Jun 2010 21:24 On Jun 7, 6:59 pm, Andrew Duncan <andrew.dun...(a)sonos.com> wrote: > As a mathematician, and compiler writer for the last twenty years or so, > I am aware of that. > > Joel VanderWerf wrote: > > Andrew Duncan wrote: > >> But (as I now learn as I delve further into canonical Ruby syntax) it is > >> a "feature" that 5/2 evaluates to 2 and not 2.5. So something of the > >> sort is happening here. > > > Many languages, including C, do integer division that way. > > -- > Posted viahttp://www.ruby-forum.com/. Using Ruby 1.8.7-p249 installed with rvm: I get this: ----------------------------------------- require 'complex' Complex(1,1)**-1 => Complex(0.5, -0.5) 1/Complex(1,1) => Complex(0, -1) ----------------------------------------- But, when I use the 'mathn' lib I get: require 'mathn' Complex(1,1)**-1 => Complex(1/2, -1/2) 1/Complex(1,1) => Complex(1/2, -1/2) ----------------------------------------- So require the mathn library first for 1.8.7 to get correct results. For 1.9.1 and 1.9.2 I also get correct results for both cases straight out of the box.
From: Joel VanderWerf on 7 Jun 2010 22:48 Andrew Duncan wrote: > As a mathematician, and compiler writer for the last twenty years or so, > I am aware of that. > > Joel VanderWerf wrote: >> Andrew Duncan wrote: >>> But (as I now learn as I delve further into canonical Ruby syntax) it is >>> a "feature" that 5/2 evaluates to 2 and not 2.5. So something of the >>> sort is happening here. >> Many languages, including C, do integer division that way. Sorry (*blush*). It's just a knee-jerk reaction to newcomers to this list who start talking about a "feature" of ruby that cannot possibly be correct and must be changed. Again, I apologize for that (and for assuming you are a newb).
From: Robert Dober on 8 Jun 2010 04:11 On Mon, Jun 7, 2010 at 9:38 PM, Andrew Duncan <andrew.duncan(a)sonos.com> wrote: > I have ruby 1.8.7 (2009-06-08 patchlevel 173) [universal-darwin10.0] > > BTW, I hope that was 1/2 - 1/2i in your post... That is how Irb shows them, why not provide a patch? We are spoiled, aren't we? No offense intended I mean we are indeed *spoiled* by what we get for free, and sometimes things are not perfect. Cheers R. -- The best way to predict the future is to invent it. -- Alan Kay
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