Function for Data Transformations

Description

Transformations of Response or Input Variables

Usage

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ptrafo(data, numeric_trafo = id_trafo, factor_trafo = ff_trafo, 
    ordered_trafo = of_trafo, surv_trafo = logrank_trafo, 
    var_trafo = NULL)
ff_trafo(x)

Arguments

data

an object of class data.frame.

numeric_trafo

a function to by applied to numeric elements of data returning a matrix with nrow(data) rows and an arbitrary number of columns.

ordered_trafo

a function to by applied to ordered elements of data returning a matrix with nrow(data) rows and an arbitrary number of columns (usually some scores).

factor_trafo

a function to by applied to factor elements of data returning a matrix with nrow(data) rows and an arbitrary number of columns (usually a dummy or contrast matrix).

surv_trafo

a function to by applied to elements of class Surv of data returning a matrix with nrow(data) rows and an arbitrary number of columns.

var_trafo

an optional named list of functions to be applied to the corresponding variables in data.

x

a factor

Details

trafo applies its arguments to the elements of data according to the classes of the elements. See Transformations for more documentation and examples.

In the presence of missing values, one needs to make sure that all user-supplied functions deal with that.

Value

A named matrix with nrow(data) rows and arbitrary number of columns.

Examples

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  ### rank a variable
  ptrafo(data.frame(y = 1:20), 
         numeric_trafo = function(x) rank(x, na.last = "keep"))

  ### dummy coding of a factor
  ptrafo(data.frame(y = gl(3, 9)))