Hi,All, Construct a list: [0,0.1..1] ==================================== || || || || || || ||__ Hugs 98: Based on the Haskell 98 standard ||___|| ||__|| ||__|| __|| Copyright (c) 1994-2005 ||---|| ___|| World Wide Web: http://haskell.org/hugs || || Bugs: http://hackage.haskell.org/trac/hugs || || Version: September 2006 _________________________________________ Haskell 98 mode: Restart with command line option -98 to enable extensions Type :? for help Hugs> [0,0.1..1] [0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0] Hugs> ==================================== GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help Loading package base ... linking ... done. Prelude> [0,0.1..1] [0.0,0.1,0.2,0.30000000000000004,0.4,0.5,0.6,0.7,0.7999999999999999,0.8999999999999999,0.9999999999999999] Prelude> ==================================== Thanks. -- Regards, Linker Lin linker.m.lin@gmail.com
This looks like Hugs defaulting to a different type to ghci, specifically, Hugs is defaulting to one of the high precission types like CReal or Rational, while ghci is defaulting to Float or Double. Bob On 24 Jun 2009, at 21:03, Linker wrote:
Hi,All, Construct a list: [0,0.1..1]
==================================== || || || || || || ||__ Hugs 98: Based on the Haskell 98 standard ||___|| ||__|| ||__|| __|| Copyright (c) 1994-2005 ||---|| ___|| World Wide Web: http://haskell.org/ hugs || || Bugs: http://hackage.haskell.org/trac/hugs || || Version: September 2006 _________________________________________
Haskell 98 mode: Restart with command line option -98 to enable extensions
Type :? for help Hugs> [0,0.1..1] [0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0] Hugs>
==================================== GHCi, version 6.8.2: http://www.haskell.org/ghc/ :? for help Loading package base ... linking ... done. Prelude> [0,0.1..1] [0.0,0.1,0.2,0.30000000000000004,0.4,0.5,0.6,0.7,0.7999999999999999,0.8999999999999999,0.9999999999999999 ] Prelude>
==================================== Thanks.
-- Regards, Linker Lin linker.m.lin@gmail.com _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Am Mittwoch 24 Juni 2009 21:05:50 schrieb Thomas Davie:
This looks like Hugs defaulting to a different type to ghci, specifically, Hugs is defaulting to one of the high precission types like CReal or Rational, while ghci is defaulting to Float or Double.
Bob
No, hugs is displaying with fewer digits of precision, so the round for display gives 0.x000000 which is abbreviated to 0.x, ghci displays with more digits, so the floating point inexactness shows in the last digit. Prelude> sin 2 0.9092974268256817 Hugs> sin 2 0.909297426825682
Linker wrote:
Hugs> [0,0.1..1] [0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0]
Prelude> [0,0.1..1] [0.0,0.1,0.2,0.30000000000000004,0.4,0.5,0.6,0.7,0.7999999999999999,0.8999999999999999,0.9999999999999999]
Just floating point errors. In this case, you may be able to get away with something like this: Prelude> map ((/10) . fromIntegral) [0..10] [0.0,0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0] - Jake
participants (5)
-
Bulat Ziganshin -
Daniel Fischer -
Jake McArthur -
Linker -
Thomas Davie