Unless I missed something, the function in question is: sqrt (a * a + 2 + 2 * num) - fromIntegral a where num = 10
1 -> sqrt (1 * 1 + 2 + 2 * 10) - 1 -> sqrt (1 + 2 + 20) - 1 -> sqrt (23) - 1 -> 3.79xxxxx the fractional will only ever come from the sqrt function. Do any of the following actually look like square values to you? 26 31 38 47 58 71 86 103 122 IMO, the code works and your expectations are a bit off. Thomas On Mon, Sep 28, 2009 at 11:54 PM, Magicloud Magiclouds <[email protected]> wrote: > The original code is > givenSum num = map (\a -> > let l = (sqrt $ fromIntegral (a * a + 2 + 2 * > num)) - (fromIntegral a) in > case properFraction l of > (_, 0) -> > True > _ -> > False > ) $ take num [1..] > :t l is (Floating a) => a > Well, in ghci > *Main> givenSum 10 > [False,False,False,False,False,False,False,False,False,False] > > On Tue, Sep 29, 2009 at 2:45 PM, Thomas DuBuisson > <[email protected]> wrote: >> On Mon, Sep 28, 2009 at 11:35 PM, Magicloud Magiclouds >> <[email protected]> wrote: >>> It never matches to (_, 0.0).... >>> I mean >>> case properFraction l of >>> (_, 0) -> l >>> _ -> 0 -- always goes here. >> >> Odd, it works fine for me. >> >> f x = >> case properFraction x of >> (_,0) -> True >> _ -> False >> >> >> *Main> f 5 >> True >> *Main> f 5.5 >> False >> *Main> f 4.0 >> True >> *Main> f 4.00000001 >> False >> >> >> Thomas >> > > > > -- > 竹密岂妨流水过 > 山高哪阻野云飞 > _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
