anova.negbin {MASS} | R Documentation |
Method function to perform sequential likelihood ratio tests for Negative Binomial generalized linear models.
## S3 method for class 'negbin' anova(object, ..., test = "Chisq")
object |
Fitted model object of class |
... |
Zero or more additional fitted model objects of class |
test |
Argument to match the |
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.
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.
Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.
glm.nb
, negative.binomial
, summary.negbin
m1 <- glm.nb(Days ~ Eth*Age*Lrn*Sex, quine, link = log) m2 <- update(m1, . ~ . - Eth:Age:Lrn:Sex) anova(m2, m1) anova(m2)