gamlss (version 4.2-8)

plot2way: Function to plot two interaction in a GAMLSS model

Description

This function is designed to plot a factor to factor interaction in a GAMLSS model.

Usage

plot2way(obj, terms = list(), what = c("mu", "sigma", "nu", "tau"), 
        show.legend = TRUE, ...)

Arguments

obj

A gamlss model

terms

this should be a character vector with the names of the two factors to be plotted

what

which parameters? mu, sigma, nu, or tau

show.legend

whether to show the legend in the two way plot

...

Further arguments

Value

• The function creates a 2 way interaction plot

Details

This is an experimental function which should be use with prudence since no other check is done on whether this interaction interfere with other terms in the model

References

Rigby, R. A. and Stasinopoulos D. M. (2005). Generalized additive models for location, scale and shape,(with discussion), Appl. Statist., 54, part 3, pp 507-554.

Stasinopoulos D. M., Rigby R.A. and Akantziliotou C. (2006) Instructions on how to use the GAMLSS package in R. Accompanying documentation in the current GAMLSS help files, (see also http://www.gamlss.org/).

Stasinopoulos D. M. Rigby R.A. (2007) Generalized additive models for location scale and shape (GAMLSS) in R. Journal of Statistical Software, Vol. 23, Issue 7, Dec 2007, http://www.jstatsoft.org/v23/i07.

See Also

term.plot,

Examples

data(aids)
ti <- factor(c(rep(1,18),rep(2,27))) 
m1 <- gamlss(y~x+qrt*ti, data=aids, family=NBI)
m2 <- gamlss(y~x+qrt*ti, data=aids, family=NO)
plot2way(m1, c("qrt","ti")) 
plot2way(m1, c("ti", "qrt"))