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Subject: [boost] Log/tropical semiring for boost math
From: Alex Graves (alex.graves_at_[hidden])
Date: 20100410 08:46:46
Hi,
I work in machine learning, and often need to do probability computations in
the log scale to avoid underflows. A nice way to do this is to use a class
where the add, divide etc. operators are overloaded by their log scale
equivalents (e.g. log(a*b) = log(a) + log(b)). In other words a class
implementing the log semiring <http://en.wikipedia.org/wiki/Semiring>. Also
useful in this context is the tropical semiring, where adding is replaced by
taking the maximum (or minimum) of the arguments. I looked for these in the
boost math library, but couldn't find anything. So I wrote my own. Did I
miss something? And if not, is anyone interested in adding my implementation
to boost math?
Alex
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