column_transformation: Pure column transformations.

In robertzk/mungebits: mungebits (http://github.com/robertzk/mungebits)

Description

A mungebit which affects multiple columns identically and independently can be abstracted into a column transformation. This function allows one to specify what happens to an individual column, and the mungebit will be the resulting column transformation applied to an arbitrary combination of columns.

Usage

column_transformation(transformation, mutating = FALSE, named = FALSE)

Arguments

transformation	a function. The only argument should be the original column.
mutating	a logical. Announces whether the transformation passed in attempts to maintain state between prediction and training runs using the "inputs" global.
named	a logical. Whether or not the transformation should be passed an atomic vector, or a list of length 1 whose single element is given the same name as the column currently being processed.

Value

a function which takes a data.frame and a vector of columns and applies the transformation.

See Also

multi_column_transformation

Examples

doubler <- column_transformation(function(x) 2*x)
# doubles the Sepal.Length column in the iris dataset
doubler(iris, c('Sepal.Length'))

robertzk/mungebits documentation built on May 27, 2019, 10:35 a.m.