Hello Daniel,
Friday, May 21, 2010, 11:55:35 PM, you wrote:
xf = (fromRational $ toRational xd) :: Float
xf = double2Float xd
am still surprised how often such kinds of unobvious problems occur
while programming in Haskell
does it mean that all other languages you are used doesn't have
Daniel Fischer wrote:
There are more rules elsewhere. If you compile with optimisations, GHC
turns your realToFrac into double2Float# nicely, so it's okay to use
realToFrac.
However, without optimisations, no rules fire, so you'll get
(fromRational . toRational).
That must be new, because it
On Sunday 23 May 2010 13:12:16, wren ng thornton wrote:
Daniel Fischer wrote:
There are more rules elsewhere. If you compile with optimisations, GHC
turns your realToFrac into double2Float# nicely, so it's okay to use
realToFrac.
However, without optimisations, no rules fire, so you'll
Dear Haskellers,
I just want to share an observation. I had to convert a Double to a
Float value in an inner loop of an application, and I used somethin like
this:
xf = (fromRational $ toRational xd) :: Float
The program works on windows but it did not on OSX - it was too slow.
Now, after
On Fri, 21 May 2010, Daniel van den Eijkel wrote:
Dear Haskellers,
I just want to share an observation. I had to convert a Double to a Float
value in an inner loop of an application, and I used somethin like this:
xf = (fromRational $ toRational xd) :: Float
I think realToFrac is the
I see. And I changed the code, it works well. Thanks for that!
Daniel
Henning Thielemann schrieb:
On Fri, 21 May 2010, Daniel van den Eijkel wrote:
Dear Haskellers,
I just want to share an observation. I had to convert a Double to a
Float value in an inner loop of an application, and I
On Friday 21 May 2010 22:06:43, Henning Thielemann wrote:
On Fri, 21 May 2010, Daniel van den Eijkel wrote:
Dear Haskellers,
I just want to share an observation. I had to convert a Double to a
Float value in an inner loop of an application, and I used somethin
like this:
xf =
dvde:
Dear Haskellers,
I just want to share an observation. I had to convert a Double to a
Float value in an inner loop of an application, and I used somethin like
this:
xf = (fromRational $ toRational xd) :: Float
The program works on windows but it did not on OSX - it was too slow.
By the way, speaking of floating-point precision, is there a real reason why
haskell forces us to write :
foreign import ccall unsafe math.h frexp c_frexp::CDouble-(Ptr CInt)-IO ()
foreign import ccall unsafe math.h ldexp c_ldexp::CDouble-CInt-IO CDouble
ulp::Double-Double
ulp x=unsafePerformIO
