gss (version 2.2-9)

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 $$(f(1)-f(.){)}^2+\cdots +(f(k)-f(.){)}^2$$ where $f(.)=(f(1)+\cdots +f(k))/k$.

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

See Also

mkterm, mkrk.cubic, and mkrk.tp.