R: FlexMix Interface to GLMs with Fixed Coefficients

FLXMRglmfix {flexmix} | R Documentation

## FlexMix Interface to GLMs with Fixed Coefficients

### Description

This implements a driver for FlexMix which interfaces the `glm` family of models and where it is possible to specify fixed (constant) or nested varying coefficients or to ensure that in the Gaussian case the variance estimate is equal for all components.

### Usage

    FLXMRglmfix(formula = . ~ ., fixed = ~0, varFix = FALSE, nested = NULL,
           family = c("gaussian", "binomial", "poisson", "Gamma"),
           offset = NULL)

### Arguments

`formula` | A formula which is interpreted relative to the formula specified in the call to `flexmix` using `update.formula`. Default is to use the original `flexmix` model formula.
`fixed` | A formula which specifies the additional regressors for the fixed (constant) coefficients.
`varFix` | A logical indicating if the variance estimate for Gaussian components should be constrained to be equal for all components. It can be also a vector specifying the number of components with equal variance.
`nested` | An object of class `FLXnested` or a list specifying the nested structure.
`family` | A character string naming a `glm` family function.
`offset` | This can be used to specify an a priori known component to be included in the linear predictor during fitting.

### Value

Returns an object of class `FLXMRglmfix`.

### Author(s)

Friedrich Leisch and Bettina Gruen

### See Also

`FLXMRglm`

### Examples

    data("NPreg", package = "flexmix")
    ex <- flexmix(yn ~ x | id2, data = NPreg, k = 2,
                  cluster = NPreg$class,
                  model = FLXMRglm(yn ~ . + I(x^2)))
    ex.fix <- flexmix(yn ~ x | id2, data = NPreg,
                      cluster = posterior(ex),
                      model = FLXMRglmfix(nested = list(k = c(1, 1),
                                          formula = c(~0, ~I(x^2)))))
    summary(refit(ex))
    ## Not run:
    summary(refit(ex.fix))

    ## End(Not run)

[Package flexmix version 2.3-14 Index]