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)

Arguments

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

Value

A list of two elements.

Note

mkrk.x create a bivariate function fun(x,y,env,outer=FALSE), where x, y are real arguments and local constants can be passed in through env.

See Also

mkterm, mkrk.cubic, and mkrk.tp.