Safe Haskell	None
Language	Haskell2010

DataFrame.Internal.AggKernel

Description

Vectorized scatter-accumulate aggregation kernel.

Synopsis

data Reduction
- = RSum
- | RCount
- | RMin
- | RMax
- | RMean
- | RStd
- | RVar
- | RTop2Sum
scatterReduce :: Reduction -> Vector Int -> Int -> Column -> Maybe Column
scatterColumnToDouble :: Column -> Maybe (Vector Double)

Documentation

data Reduction Source #

A recognised fast-path reduction over a single value column. The element type (Int vs Double) is resolved at scatter time; summinmax preserve the column's element type, everything else produces a Double column.

Constructors

RSum
RCount
RMin
RMax
RMean
RStd
RVar
RTop2Sum

Instances

Instances details

Show Reduction Source #
Instance details Defined in DataFrame.Internal.AggKernel Methods showsPrec :: Int -> Reduction -> ShowS # show :: Reduction -> String # showList :: [Reduction] -> ShowS #
Eq Reduction Source #
Instance details Defined in DataFrame.Internal.AggKernel Methods (==) :: Reduction -> Reduction -> Bool # (/=) :: Reduction -> Reduction -> Bool #

scatterReduce :: Reduction -> Vector Int -> Int -> Column -> Maybe Column Source #

scatterColumnToDouble :: Column -> Maybe (Vector Double) Source #

Coerce an unboxed Int or Double column to an unboxed Double vector for the momentmeansd/median family. Returns Nothing for boxed, nullable, or other element types (the caller then falls back to the interpreter).