choose.fx {mbrdr}

choose fx for principal fitted response reduction and unstructured principal fitted response reduction

Description

Returns a n \times q matrix used in principal fitted response reduction and unstructured principal fitted response reduction.

Usage

choose.fx(X, fx.choice=1, nclust = 5)

Arguments

X

n \times p predictor matrix

fx.choice

four choices for fx; see below

nclust

the number of clusters; see below

Details

Both of principal fitted response reduction and unstructured principal fitted response reduction require a choice of fx. The function will return one of four choices of fx, which are popular candidates among many.

fx.choice=1: This is default and returns the original predictor matrice X, centered at zero as fx.

fx.choice=2: This returns the original predictor matrice X, centered at zero and its squared values.

fx.choice=3: This returns the original predictor matrice X, centered at zero and its exponentiated values.

fx.choice=4: This clusters X with K-means algoritm with the number of clusters equal to the value in nclust. Then, the cluster results are expanded to \code{nclust}-1 dummy variables, like factor used in lm function. Finally, it returns nclust-1 categorical basis. The option of nclust works only with fx.choice=4.

Value

A n \times q matrix for fx.

Author(s)

Jae Keun Yoo, [e-mail]

Examples

data(mps)
X <- mps[,c(5:6,8:14)]
choose.fx(X)

choose.fx(X, fx.choice=2)

choose.fx(X, fx.choice=4, nclust=3)