calibration: Calibrating centile curves

Description Usage Arguments Details Value Author(s) References See Also Examples

View source: R/lms.R

Description

This function can used when the fitted model centiles do not coincide with the sample centiles.

Usage

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calibration(object, xvar, cent = c(0.4, 2, 10, 25, 50, 75, 90, 98, 99.6),
            legend = FALSE, fan = FALSE, ...)

Arguments

object

a gamlss fitted object

xvar

The explanatory variable

cent

a vector with elements the % centile values for which the centile curves have to be evaluated

legend

whether legend is required

fan

whether to use the fan version of centiles

...

other argument pass on to centiles() function

Details

The function finds the sample quantiles of the residuals of the fitted model (the z-scores) and use them as sample quantile in the argument cent of the centiles() function. This procedure is appropriate if the fitted model centiles do not coincide with the sample centiles and when this failure is the same in all values of the explanatory variable xvar.

Value

A centile plot is produced and the sample centiles below each centile curve are printed (or saved)

Author(s)

Mikis Stasinopoulos d.stasinopoulos@londonmet.ac.uk, Bob Rigby r.rigby@londonmet.ac.uk and Vlasios Voudouris

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

centiles, centiles.fan

Examples

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data(abdom)
m1<-gamlss(y~pb(x), sigma.fo=~pb(x), family=LO, data=abdom)
calibration(m1, xvar=abdom$x, fan=TRUE)

Example output

Loading required package: splines
Loading required package: gamlss.data
Loading required package: gamlss.dist
Loading required package: MASS
Loading required package: nlme
Loading required package: parallel
 **********   GAMLSS Version 5.0-2  ********** 
For more on GAMLSS look at http://www.gamlss.org/
Type gamlssNews() to see new features/changes/bug fixes.

GAMLSS-RS iteration 1: Global Deviance = 4782.6 
GAMLSS-RS iteration 2: Global Deviance = 4779.267 
GAMLSS-RS iteration 3: Global Deviance = 4779.279 
GAMLSS-RS iteration 4: Global Deviance = 4779.279 

gamlss documentation built on March 31, 2021, 5:10 p.m.