{-# LANGUAGE FlexibleContexts #-}

-- |
-- Module    : Statistics.Sample.Internal
-- Copyright : (c) 2013 Bryan O'Sullivan
-- License   : BSD3
--
-- Maintainer  : bos@serpentine.com
-- Stability   : experimental
-- Portability : portable
--
-- Internal functions for computing over samples.
module Statistics.Sample.Internal
    (
      robustSumVar
    , sum
    ) where

import Numeric.Sum (kbn, sumVector)
import Prelude hiding (sum)
import Statistics.Function (square)
import qualified Data.Vector.Generic as G

robustSumVar :: (G.Vector v Double) => Double -> v Double -> Double
robustSumVar :: forall (v :: * -> *).
Vector v Double =>
Double -> v Double -> Double
robustSumVar Double
m = v Double -> Double
forall (v :: * -> *). Vector v Double => v Double -> Double
sum (v Double -> Double)
-> (v Double -> v Double) -> v Double -> Double
forall b c a. (b -> c) -> (a -> b) -> a -> c
. (Double -> Double) -> v Double -> v Double
forall (v :: * -> *) a b.
(Vector v a, Vector v b) =>
(a -> b) -> v a -> v b
G.map (Double -> Double
square (Double -> Double) -> (Double -> Double) -> Double -> Double
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Double -> Double -> Double
forall a. Num a => a -> a -> a
subtract Double
m)
{-# INLINE robustSumVar #-}

sum :: (G.Vector v Double) => v Double -> Double
sum :: forall (v :: * -> *). Vector v Double => v Double -> Double
sum = (KBNSum -> Double) -> v Double -> Double
forall (v :: * -> *) s.
(Vector v Double, Summation s) =>
(s -> Double) -> v Double -> Double
sumVector KBNSum -> Double
kbn
{-# INLINE sum #-}