[Python-Dev] Rational approximation methods (original) (raw)

Leif Walsh adlaiff6 at gmail.com
Sun Jan 20 20:25:29 CET 2008

On 1/20/08, Paul Moore <p.f.moore at gmail.com> wrote:

Both of these are likely to be of limited use. The most common usage I know of is to make a "sensible" rational from a float (i.e., a DWIM style conversion 0.1 -> 1/10) or to provide readable output. On the other hand, both are subtle to implement, so having a standard implementation saves people having to code (and debug) their own.

I suspect that simplest within a particular distance is the form that is most often wanted, but I don't have any good evidence for that feeling. Putting both in might help people to realise that there is a choice. Given that you have implemented them, I'd say leave them in. And I like the names trim and approximate, as given in the code you referenced.

I can't think of a use case for these either, but the first (limit_denominator) seems like a generalized round, and I suppose might be useful for something.

-- Cheers, Leif

More information about the Python-Dev mailing list