lme4: nlformula – R documentation

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lme4

nlformula

Manipulate a Nonlinear Model Formula

Description

Check and manipulate the formula for a nonlinear model, such as specified in nlmer.

Usage

nlformula(mc)

Arguments

mc

matched call from the calling function, typically nlmer(). Should have arguments named

formula:

a formula of the form resp ~ nlmod ~ meform where resp is an expression for the response, nlmod is the nonlinear model expression and meform is the mixed-effects model formula. resp can be omitted when, e.g., optimizing a design.

data:

a data frame in which to evaluate the model function

start:

either a numeric vector containing initial estimates for the nonlinear model parameters or a list with components

nlpars:: the initial estimates of the nonlinear model parameters
theta:: the initial estimates of the variance component parameters

Details

The model formula for a nonlinear mixed-effects model is of the form resp ~ nlmod ~ mixed where resp is an expression (usually just a name) for the response, nlmod is the call to the nonlinear model function, and mixed is the mixed-effects formula defining the linear predictor for the parameter matrix. If the formula is to be used for optimizing designs, the resp part can be omitted.

Value

a list with components

`"respMod"`	a response module of class `"nlsResp"`
`"frame"`	the model frame, including a terms attribute
`"X"`	the fixed-effects model matrix
`"reTrms"`	the random-effects terms object

Douglas Bates [aut] (<https://orcid.org/0000-0001-8316-9503>), Martin Maechler [aut] (<https://orcid.org/0000-0002-8685-9910>), Ben Bolker [aut, cre] (<https://orcid.org/0000-0002-2127-0443>), Steven Walker [aut] (<https://orcid.org/0000-0002-4394-9078>), Rune Haubo Bojesen Christensen [ctb] (<https://orcid.org/0000-0002-4494-3399>), Henrik Singmann [ctb] (<https://orcid.org/0000-0002-4842-3657>), Bin Dai [ctb], Fabian Scheipl [ctb] (<https://orcid.org/0000-0001-8172-3603>), Gabor Grothendieck [ctb], Peter Green [ctb] (<https://orcid.org/0000-0002-0238-9852>), John Fox [ctb], Alexander Bauer [ctb], Pavel N. Krivitsky [ctb, cph] (<https://orcid.org/0000-0002-9101-3362>, shared copyright on simulate.formula)

Initial release