log-domain 0.8.1 → 0.9

raw patch · 2 files changed

+32/−4 lines, 2 files

Files

• log-domain.cabal +1/−1
• src/Numeric/Log.hs +31/−3

@@ -1,6 +1,6 @@ name:          log-domain category:      Numeric-version:       0.8.1+version:       0.9 license:       BSD3 cabal-version: >= 1.8 license-file:  LICENSE

@@ -195,12 +195,12 @@   {-# INLINE (*) #-}   Exp a + Exp b     | a == b && isInfinite a && isInfinite b = Exp a-    | a >= b    = Exp (a + log1p (exp (b - a)))-    | otherwise = Exp (b + log1p (exp (a - b)))+    | a >= b    = Exp (a + log1pexp (b - a))+    | otherwise = Exp (b + log1pexp (a - b))   {-# INLINE (+) #-}   Exp a - Exp b     | a == negInf && b == negInf = Exp negInf-    | otherwise = Exp (a + log1p (negate (exp (b - a))))+    | otherwise = Exp (a + log1mexp (b - a))   {-# INLINE (-) #-}   signum (Exp a)     | a == negInf = 0@@ -375,6 +375,10 @@   -- | Computes @log(1 + x)@   --   -- This is far enough from 0 that the Taylor series is defined.+  --+  -- This can provide much more accurate answers for logarithms of numbers close to 1 (x near 0).+  --+  -- These arise when working wth log-scale probabilities a lot.   log1p :: a -> a    -- | The Taylor series for exp(x) is given by@@ -391,17 +395,41 @@   -- algebraically to provide the 1 by other means.   expm1 :: a -> a +  log1pexp :: a -> a+  log1pexp a = log1p (exp a)++  log1mexp :: a -> a+  log1mexp a = log1p (negate (exp (negate a)))+ instance Precise Double where   log1p = c_log1p   {-# INLINE log1p #-}   expm1 = c_expm1   {-# INLINE expm1 #-}+  log1mexp a+    | a <= log 2 = log (negate (expm1 (negate a)))+    | otherwise  = log1p (negate (exp (negate a)))+  {-# INLINE log1mexp #-}+  log1pexp a+    | a <= 18   = log1p (exp a)+    | a <= 100  = a + exp (negate a)+    | otherwise = a+  {-# INLINE log1pexp #-} + instance Precise Float where   log1p = c_log1pf   {-# INLINE log1p #-}   expm1 = c_expm1f   {-# INLINE expm1 #-}+  log1mexp a | a <= log 2 = log (negate (expm1 (negate a)))+             | otherwise  = log1p (negate (exp (negate a)))+  {-# INLINE log1mexp #-}+  log1pexp a+    | a <= 18   = log1p (exp a)+    | a <= 100  = a + exp (negate a)+    | otherwise = a+  {-# INLINE log1pexp #-}  instance (RealFloat a, Precise a) => Precise (Complex a) where   expm1 x@(a :+ b)