glsControl {nlme} | R Documentation

## Control Values for gls Fit

### Description

The values supplied in the function call replace the defaults and a list with all possible arguments is returned. The returned list is used as the `control` argument to the `gls` function.

### Usage

    glsControl(maxIter, msMaxIter, tolerance, msTol, msVerbose,
               singular.ok, returnObject, apVar, .relStep,
               opt=c("nlminb", "optim"), optimMethod,
               minAbsParApVar, natural, sigma = NULL)

### Arguments

`maxIter` | maximum number of iterations for the `gls` optimization algorithm. Default is 50.
`msMaxIter` | maximum number of iterations for the optimization step inside the `gls` optimization. Default is 50.
`tolerance` | tolerance for the convergence criterion in the `gls` algorithm. Default is 1e-6.
`msTol` | tolerance for the convergence criterion of the first outer iteration when `optim` is used. Default is 1e-7.
`msVerbose` | a logical value passed as the `trace` argument to `ms` (see documentation on that function). Default is `FALSE`.
`singular.ok` | a logical value indicating whether non-estimable coefficients (resulting from linear dependencies among the columns of the regression matrix) should be allowed. Default is `FALSE`.
`returnObject` | a logical value indicating whether the fitted object should be returned when the maximum number of iterations is reached without convergence of the algorithm. Default is `FALSE`.
`apVar` | a logical value indicating whether the approximate covariance matrix of the variance-covariance parameters should be calculated. Default is `TRUE`.
`.relStep` | relative step for numerical derivatives calculations. Default is `.Machine$double.eps^(1/3)`.
`opt` | the optimizer to be used, either `"nlminb"` (the current default) or `"optim"` (the previous default).
`optimMethod` | character - the optimization method to be used with the `optim` optimizer. The default is `"BFGS"`. An alternative is `"L-BFGS-B"`.
`minAbsParApVar` | numeric value - minimum absolute parameter value in the approximate variance calculation. The default is `0.05`.
`natural` | logical. Should the natural parameterization be used for the approximate variance calculations? Default is `TRUE`.
`sigma` | optionally a positive number to fix the residual error at. If `NULL`, as by default, or `0`, sigma is estimated.

### Value

a list with components for each of the possible arguments.

### Author(s)

José Pinheiro and Douglas Bates bates@stat.wisc.edu; the `sigma` option: Siem Heisterkamp and Bert van Willigen.

### See Also

`gls`

### Examples

    # decrease the maximum number iterations in the optimization call and
    # request that information on the evolution of the ms iterations be printed
    glsControl(msMaxIter = 20, msVerbose = TRUE)

[Package nlme version 3.1-131 Index]