FormulaMethods {rmutil}

Methods for formulafn Functions

Description

Methods for accessing the contents of a function created from formula produced by finterp or a function modified by fnenvir.

covariates: extract the names of the covariates.

formula: extract the formula used to produce the function (finterp only).

model: extract the model function or model matrix if W&R notation was used.

parameters: extract the names of the parameters.

Usage

## S3 method for class 'formulafn'
covariates(z, ...)
## S3 method for class 'formulafn'
formula(x, ...)
model(z, ...)
parameters(z, ...)
## S3 method for class 'formulafn'
print(x, ...)

Arguments

x, z

A function of class, formulafn.

...

Arguments to other functions.

Value

These methods extract information about functions of class, formulafn, created by finterp or fnenvir.

Author(s)

J.K. Lindsey

See Also

finterp, fnenvir.

Examples

x1 <- rpois(20,2)
x2 <- rnorm(20)
#
# Wilkinson and Rogers formula with three parameters
fn1 <- finterp(~x1+x2)
fn1
covariates(fn1)
formula(fn1)
model(fn1)
parameters(fn1)
#
# nonlinear formula with unknowns
fn2 <- finterp(~exp(b0+b1*x1+b2*x2))
fn2
covariates(fn2)
formula(fn2)
model(fn2)
parameters(fn2)
#
# function transformed by fnenvir
fn3 <- fnenvir(function(p) p[1]+p[2]*x1)
covariates(fn3)
formula(fn3)
model(fn3)
parameters(fn3)