glsObject {nlme} | R Documentation

## Fitted gls Object

### Description

An object returned by the `gls` function, inheriting from class `gls` and representing a generalized least squares fitted linear model. Objects of this class have methods for the generic functions `anova`, `coef`, `fitted`, `formula`, `getGroups`, `getResponse`, `intervals`, `logLik`, `plot`, `predict`, `print`, `residuals`, `summary`, and `update`.

### Value

The following components must be included in a legitimate `gls` object.

`apVar` | an approximate covariance matrix for the variance-covariance coefficients. If `apVar = FALSE` in the list of control values used in the call to `gls`, this component is equal to `NULL`.
`call` | a list containing an image of the `gls` call that produced the object.
`coefficients` | a vector with the estimated linear model coefficients.
`contrasts` | a list with the contrasts used to represent factors in the model formula. This information is important for making predictions from a new data frame in which not all levels of the original factors are observed. If no factors are used in the model, this component will be an empty list.
`dims` | a list with basic dimensions used in the model fit, including the components `N` - the number of observations in the data and `p` - the number of coefficients in the linear model.
`fitted` | a vector with the fitted values..
`glsStruct` | an object inheriting from class `glsStruct`, representing a list of linear model components, such as `corStruct` and `varFunc` objects.
`groups` | a vector with the correlation structure grouping factor, if any is present.
`logLik` | the log-likelihood at convergence.
`method` | the estimation method: either `"ML"` for maximum likelihood, or `"REML"` for restricted maximum likelihood.
`numIter` | the number of iterations used in the iterative algorithm.
`residuals` | a vector with the residuals.
`sigma` | the estimated residual standard error.
`varBeta` | an approximate covariance matrix of the coefficients estimates.

### Author(s)

Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates bates@stat.wisc.edu

### See Also

`gls`, `glsStruct`

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