R: Calculate nlmeStruct Residuals

residuals.nlmeStruct {nlme}

R Documentation

Calculate nlmeStruct Residuals

Description

The residuals at level i are obtained by subtracting the fitted values at that level from the response vector. The fitted values at level i are obtained by adding together the contributions from the estimated fixed effects and the estimated random effects at levels less or equal to i and evaluating the model function at the resulting estimated parameters.

Usage

## S3 method for class 'nlmeStruct'
residuals(object, level, conLin, ...)

Arguments

`object`	an object inheriting from class `"nlmeStruct"`, representing a list of mixed-effects model components, such as `reStruct`, `corStruct`, and `varFunc` objects.
`level`	an optional integer vector giving the level(s) of grouping to be used in extracting the residuals from `object`. Level values increase from outermost to innermost grouping, with level zero corresponding to the population fitted values. Defaults to the highest or innermost level of grouping.
`conLin`	an optional condensed linear model object, consisting of a list with components `"Xy"`, corresponding to a regression matrix (`X`) combined with a response vector (`y`), and `"logLik"`, corresponding to the log-likelihood of the underlying nlme model. Defaults to `attr(object, "conLin")`.
`...`	optional arguments to the residuals generic. Not used.

Value

if a single level of grouping is specified in level, the returned value is a vector with the residuals at the desired level; else, when multiple grouping levels are specified in level, the returned object is a matrix with columns given by the residuals at different levels.

Note

This method function is primarily used within the nlme function.

Author(s)

José Pinheiro and Douglas Bates bates@stat.wisc.edu

References

Bates, D.M. and Pinheiro, J.C. (1998) "Computational methods for multilevel models" available in PostScript or PDF formats at http://nlme.stat.wisc.edu