--------------------------------------------
-- Announcing: logfloat 0.8.5
--------------------------------------------
New official release of the logfloat package for manipulating log-domain
floating numbers. This is primarily a maintenance release updating the
documentation and with minor tweaks on typeclass-restricted polymorphism.
Substantively, I also broke out a new type class for numbers which can
represent transfinite values. This is primarily to deal with issues
about Rationals and other Fractional types which cannot represent them.
I also decided to switch the code over to *.hs format so that the
Hackage build bot can generate the documentation more reliably.
--------------------------------------------
-- Description
--------------------------------------------
The main reason for casting numbers into the log-domain is to prevent
underflow when multiplying many small probabilities as is done in Hidden
Markov Models and other statistical models often used for natural
language processing. The log-domain also helps prevent overflow when
multiplying many large numbers. In rare cases it can speed up numerical
computation (since addition is faster than multiplication, though
logarithms are exceptionally slow), but the primary goal is to improve
accuracy of results. A secondary goal has been to maximize efficiency
since these computations are frequently done within a /O(n^3)/ loop.
The Data.Numeric.LogFloat module provides a new data type LogFloat which
handles all the conversions and optimizations and can be treated as any
other number thanks to type classes.
--------------------------------------------
-- 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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