R: Crafting Building Blocks for Discrete Splines

mkrk.nominal {gss} | R Documentation

## 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

`levels` | Levels of the factor.

### Details

For a nominal factor with levels 1,2,…,k, the level means f(i) will be shrunk towards each other through a penalty proportional to

(f(1)-f(.))^2+…+(f(k)-f(.))^2

where f(.)=(f(1)+…+f(k))/k.

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

(f(1)-f(2))^2+…+(f(k-1)-f(k))^2

### Value

A list of two elements.

`fun` | Function definition.
`env` | Portable local constants derived from the arguments.

### 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`.

[Package gss version 2.2-2 Index]