[Haskell-cafe] floating point operations and representation

[Don Stewart]

> I am under the restriction that I need to write Haskell programs using
> Double which mimic existing C/C++ programs or generated data sets, and
> get the same answers.  (It's silly, but take it as a given
> requirement.)  If the C programs are using "log2", then I need "log2"
> in the Haskell, or else I run the risk of not producing the same
> answers. 

Hey Jacob,

Just to make life super simple, I packaged up a binding to the basic
math.h library for Doubles. You can find the library here:

    http://hackage.haskell.org/cgi-bin/hackage-scripts/package/cmath

For example,

    Prelude> Foreign.C.Math.Double.log10 5
    0.6989700043360189

    Prelude> log 5 / log 10
    0.6989700043360187

Enjoy!

-- Don