Likelihood Ratio Tests for Negative Binomial GLMs
Usage
anova.negbin(object, ..., test="Chisq")
anova(object, ..., test="Chisq")
Arguments
object
|
Fitted model object of class negbin , inheriting from classes glm and
lm , specifying a Negative Binomial fitted GLM. Typically the output of
glm.nb() .
|
...
|
Zero or more additional fitted model objects of class negbin . They
should form a nested sequence of models, but need not be specified in any
particular order.
|
test
|
Argument to match the test argument of anova.glm . Ignored (with a
warning if changed) if a sequence of two or more Negative Binomial fitted
model objects is specified, but possibly used if only one object is specified.
|
Description
Method function to perform sequential likelihood ratio tests for Negative
Binomial generalized linear models.Details
This function is a method for the generic function
anova()
for class negbin
.
It can be invoked by calling anova(x)
for an
object x
of the appropriate class, or directly by
calling anova.negbin(x)
regardless of the
class of the object.NOTE
If only one fitted model object is specified, a sequential analysis of
deviance table is given for the fitted model. The theta
parameter is kept
fixed. If more than one fitted model object is specified they must all be
of class negbin
and likelihood ratio tests are done of each model within
the next. In this case theta
is assumed to have been re-estimated for each
model.See Also
glm.nb
, negative.binomial
, summary.negbin
Examples
data(quine)
m1 <- glm.nb(Days ~ Eth*Age*Lrn*Sex, quine, link = log)
m2 <- update(m1, . ~ . - Eth:Age:Lrn:Sex)
anova(m2, m1)