Sinc function
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(Difference between revisions)
| Line 5: | Line 5: | ||
<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 sin(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
