| commit | 3f71fe3998c947cd80218406ebe9b78a4e27399e | |
| author | Nick Bowler <nbowler@draconx.ca> | |
| Fri, 19 Feb 2010 22:47:59 +0000 (19 17:47 -0500) | ||
| committer | Nick Bowler <nbowler@draconx.ca> | |
| Fri, 19 Feb 2010 22:48:08 +0000 (19 17:48 -0500) | ||
| tree | b2a8a052bdd7f930c1ba583501aef157e4e4058e | treesnapshot (tar.gz zip) |
| parent | 851ccb5520035c38a8c2103e9569c4b302aa7d80 | commitdiff |
floating: Make fromRational work properly.
The current implementation of fromRational (for both floating types) is
a simple floating point division, which does not work correctly when
either the numerator or the denominator cannot be represented exactly.
We do a correct conversion by scaling the rational by a power of two to
get a large integer that makes maximum use of the available precision.
Since such an integer is exactly representable, we can use scalb to get
the actual value.
The current implementation of fromRational (for both floating types) is
a simple floating point division, which does not work correctly when
either the numerator or the denominator cannot be represented exactly.
We do a correct conversion by scaling the rational by a power of two to
get a large integer that makes maximum use of the available precision.
Since such an integer is exactly representable, we can use scalb to get
the actual value.
| Data/Floating/Helpers.hs | [new file with mode: 0644] | blob |
| Data/Floating/Types/Double.hs | diffblobblamehistory | |
| Data/Floating/Types/Float.hs | diffblobblamehistory | |
| altfloat.cabal | diffblobblamehistory |