Data.Monoid.Average

Documentation

newtype Average a

A monoid for Average values.

This is actually just the free monoid with an extra function average for extracing the (arithmetic) mean. This function is used to implement Real, so you can use Average whenever a (Monoid, Real) is required.

>>> toRational $ mconcat [1,2::Average Rational]
3 % 2
>>> toRational $ mconcat [1,2::Sum Rational]
3 % 1
>>> toRational $ mconcat [1,2::Product Rational]
2 % 1

Constructors

Average

Fields

getAverage :: [a]

Instances

Functor Average

Typeable1 Average

Applicative Average

(Fractional a, Eq a) => Eq (Average a)

Floating a => Floating (Average a)

(Fractional a, Num a) => Fractional (Average a)

Num a => Num (Average a)

(Fractional a, Ord a) => Ord (Average a)

(Real a, Fractional a) => Real (Average a)

Show a => Show (Average a)

Monoid (Average a)

Semigroup (Average a)

AffineSpace a => AffineSpace (Average a)

VectorSpace a => VectorSpace (Average a)

AdditiveGroup a => AdditiveGroup (Average a)

average :: Fractional a => Average a -> a

Return the average of all monoidal components. If given mempty, return zero.

maybeAverage :: Fractional a => Average a -> Maybe a

Return the average of all monoidal components. If given mempty, return Nothing.