Sinc function
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| - | + | The sinc function, <math>\frac{sin(x)}{x}</math>, is a useful function that is a little tricky to implement because it becomes <math>\frac{0}{0}</math> as x approaches <math>0</math>. Here is an implementation taken from the [http://www.boost.org/boost/math/special_functions/sinc.hpp Boost] library. | |
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| - | The sinc function <math>\frac{sin(x)}{x}</math> is a useful function that is a little tricky to implement because it becomes 0 | + | |
<pre> | <pre> | ||
Revision as of 23:46, 14 November 2006
The sinc function, 
, is a useful function that is a little tricky to implement because it becomes 
as x approaches 0. Here is an implementation taken from the Boost library.
epsilon :: RealFloat a => a
epsilon = encodeFloat 1 (fromIntegral $ 1-floatDigits epsilon)
{- Boosted from Boost http://www.boost.org/boost/math/special_functions/sinc.hpp -}
sinc :: (RealFloat a) => a -> a
sinc x | (abs x) >= taylor_n_bound = (sin x)/x
| otherwise = 1 - (x^2/6) + (x^4/120)
where
taylor_n_bound = sqrt $ sqrt epsilon
