gss (version 2.2-8)

mkrk.nominal: Crafting Building Blocks for Discrete Splines

Description

Craft numerical functions to be used by mkterm to assemble model terms involving factors.

Usage

mkrk.nominal(levels)
mkrk.ordinal(levels)

Value

A list of two elements.

fun

Function definition.

env

Portable local constants derived from the arguments.

Arguments

levels

Levels of the factor.

Details

For a nominal factor with levels \(1,2,\dots,k\), the level means \(f(i)\) will be shrunk towards each other through a penalty proportional to $$(f(1)-f(.))^2+\dots+(f(k)-f(.))^2$$ where \(f(.)=(f(1)+\dots+f(k))/k\).

For a ordinal factor with levels \(1<2<\dots<k\), the level means \(f(i)\) will be shrunk towards each other through a penalty proportional to $$(f(1)-f(2))^2+\dots+(f(k-1)-f(k))^2$$

See Also

mkterm, mkrk.cubic, and mkrk.tp.