R: Calibrating centile curves

calibration {gamlss} | R Documentation

## Calibrating centile curves

### Description

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

### Usage

    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

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

[Package gamlss version 5.3-2 Index]