centiles.com: Comparing centiles from different GAMLSS models

In gamlss: Generalized Additive Models for Location Scale and Shape

Comparing centiles from different GAMLSS models

Description

This function compares centiles curves for more than one GAMLSS objects.It is based on the centiles function. The function also tabulates the sample percentages below each centile curve (for comparison with the model percentages given by the argument cent.) A restriction of the function is that it applies to models with one explanatory variable only

Usage

centiles.com(obj, ..., xvar, cent = c(0.4, 10, 50, 90, 99.6), 
             legend = TRUE, ylab = "y", xlab = "x", xleg = min(xvar), 
             yleg = max(obj$y), xlim = range(xvar), ylim = NULL, 
             no.data = FALSE, color = TRUE, main = NULL, plot = TRUE)

Arguments

obj	a fitted gamlss object from fitting a gamlss continuous distribution
...	optionally more fitted GAMLSS model objects
xvar	the unique explanatory variable
cent	a vector with elements the % centile values for which the centile curves have to be evaluated
legend	whether a legend is required in the plot or not, the default is legent=TRUE
ylab	the y-variable label
xlab	the x-variable label
xleg	position of the legend in the x-axis
yleg	position of the legend in the y-axis
xlim	the limits of the x-axis
ylim	the limits of the y-axis
no.data	whether the data should plotted, default no.data=FALSE or not no.data=TRUE
color	whether the fitted centiles are shown in colour, color=TRUE (the default) or not color=FALSE
main	the main title
plot	whether to plot the centiles

Value

Centile plots are produced for the different fitted models and the sample centiles below each centile curve are printed

Warning

This function is appropriate only when one continuous explanatory variable is fitted in the model

Author(s)

Mikis Stasinopoulos and Bob Rigby

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.

Rigby, R. A., Stasinopoulos, D. M., Heller, G. Z., and De Bastiani, F. (2019) Distributions for modeling location, scale, and shape: Using GAMLSS in R, Chapman and Hall/CRC. An older version can be found in https://www.gamlss.com/.

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, https://www.jstatsoft.org/v23/i07/.

Stasinopoulos D. M., Rigby R.A., Heller G., Voudouris V., and De Bastiani F., (2017) Flexible Regression and Smoothing: Using GAMLSS in R, Chapman and Hall/CRC.

(see also https://www.gamlss.com/).

See Also

gamlss, centiles , centiles.split

Examples

data(abdom)
h1<-gamlss(y~cs(x,df=3), sigma.formula=~cs(x,1),family=BCT, data=abdom)
h2<-gamlss(y~pb(x), sigma.formula=~pb(x), family=BCT, data=abdom )
centiles.com(h1,h2,xvar=abdom$x)
rm(h1,h2)

gamlss documentation built on May 29, 2024, 6:08 a.m.