--------------------------------------------
-- logfloat 0.12.1
--------------------------------------------
This package provides a type for storing numbers in the log-domain,
primarily useful for preventing underflow when multiplying many
probabilities as in HMMs and other probabilistic models. The package
also provides modules for dealing with floating numbers correctly.
--------------------------------------------
-- Changes since 0.12.0.1
--------------------------------------------
* Fixed a number of bugs where LogFloat values would become NaN when
they should not. These bugs involved using normal-space positive
infinity and so would not affect clients using the package for
probabilities.
The fixes do introduce some extra checks though. If anyone is using the
package for probabilities in a large enough project and could run some
benchmarks to see how 0.12.1 compares to 0.12.0.1 I'd love to hear the
results. (I'm not sure that doing microbenchmarks would actually give
much insight about real programs.) If the overhead is bad enough I can
add a LogProb type which ensures things are proper probabilities in
order to avoid the new checks.
--------------------------------------------
-- Compatibility / Portability
--------------------------------------------
The package is compatible with Hugs (September 2006) and GHC (6.8, 6.10,
6.12). For anyone still using GHC 6.6, the code may still work if you
replace LANGUAGE pragma by equivalent OPTIONS_GHC pragma.
The package is not compatible with nhc98 and Yhc because
Data.Number.RealToFrac uses MPTCs. The other modules should be compatible.
--------------------------------------------
-- Links
--------------------------------------------
Homepage:
http://code.haskell.org/~wren/
Hackage:
http://hackage.haskell.org/cgi-bin/hackage-scripts/package/logfloat
Darcs:
http://code.haskell.org/~wren/logfloat/
Haddock (Darcs version):
http://code.haskell.org/~wren/logfloat/dist/doc/html/logfloat/
--
Live well,
~wren
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