distribution 1.1.0.0 → 1.1.1.0

raw patch · 2 files changed

+35/−1 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• Data/Distribution/Core.hs +34/−0
• distribution.cabal +1/−1

@@ -35,6 +35,7 @@       -- ** Transformation     , select     , assuming+    , observing       -- ** Combination     , combineWith       -- ** Sequences@@ -271,6 +272,39 @@     adjust x = x * (1 / total)     total = sum $ Map.elems filtered ++-- | Returns a new distribution using the Bayesian update rule.+--+-- Using this example:+-- https://en.wikipedia.org/wiki/Bayesian_inference#Probability_of_a_hypothesis+--+-- > data CookieBowl = Bowl1 | Bowl2 deriving (Eq,Ord)+-- > data CookieType = Plain | ChocolateChip deriving (Eq,Ord)+-- >+-- > assumption :: Distribution CookieBowl+-- > assumption = uniform [Bowl1,Bowl2]+-- >+-- > update :: Cookie -> Distribution CookieBowl -> Distribution CookieBowl+-- > update c = observing f where+-- >   f b = case b of+-- >     -- Bowl #1 contains 10 chocolate chip cookies and 30 plain cookies+-- >     Bowl1 -> fromList [(c == ChocolateChip,10),(c == Plain,30)]+-- >     -- Bowl #2 contains 20 of each flavour of cookie+-- >     Bowl2 -> fromList [(c == ChocolateChip,20),(c == Plain,20)]+--+-- The "update" function in this example can be used to update the probability+-- distribution of which bowl you have based on observing a random cookie inside+-- the bowl.+observing :: (a -> Distribution Bool) -> Distribution a -> Distribution a+observing f (Distribution xs) = Distribution $ fmap adjust filtered+  where+    filtered = Map.filter (/= 0) $ Map.mapWithKey tweak xs+    tweak x p = let+      Distribution px = f x+      pt = fromMaybe 0 $ Map.lookup True px+      in pt * p+    adjust x = x * (1 / total)+    total = sum $ Map.elems filtered  -- Combination 

@@ -8,7 +8,7 @@ -- PVP summary:      +-+------- breaking API changes --                   | | +----- non-breaking API additions --                   | | | +--- code changes with no API change-version:             1.1.0.0+version:             1.1.1.0  -- A short (one-line) description of the package. synopsis:             Finite discrete probability distributions.