design_expand {lazy.tools}

R Documentation

Dummy Expantion of a Vector

Description

Dummy Expantion of a Vector

Usage

design_expand(
  x,
  type = 0,
  drop = "last",
  levels = NULL,
  froot = "level",
  sort = 0
)

Arguments

x	a vector to be expanded
type	= -1 for non-full-rank design matrix used in SAS proc GLM = 0 for zero-sum design matrix = 1 for drop-one-column design matrix
drop	= "last" or "first" when type != -1
levels	= a string vector consisting of the labels for the levels
froot	= A character to be used to name the columns of X matrix
sort	= 1 to sort the levels as the native factor function does. This is the default behavior of native model.matrix function.

Details

By default, the zero-sum design matrix with the last level dropped will be generated.

Value

Design matrix of the size length(x) times length(factor(x)) or length(x) times length(factor(x))-1

Examples

design_expand( c("a","b","c") )
design_expand( c("a","xb","c") )
design_expand( c("a","b","c"), sort=1 )

design_expand( c("a","b","c"), type=-1 )
design_expand( c("a","b","c"), levels=c("c","a","b"), type=-1 )

design_expand( 1:3, type=0 )
design_expand( c("a","b","c"), froot="A" )

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