# Sinc function

### From HaskellWiki

(Difference between revisions)

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<pre> | <pre> | ||

epsilon :: RealFloat a => a | epsilon :: RealFloat a => a | ||

− | epsilon = | + | epsilon = encodeFloat 1 (fromIntegral $ 1-floatDigits epsilon) |

{- Boosted from Boost http://www.boost.org/boost/math/special_functions/sinc.hpp -} | {- Boosted from Boost http://www.boost.org/boost/math/special_functions/sinc.hpp -} |

## Revision as of 17:56, 25 February 2006

## Sinc function

The sinc function *s**i**n*(*x*) / *x* is a useful function that is a little tricky to use because it becomes 0/0 as x tends to 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