anova.aster {aster} | R Documentation |
Compute an analysis of deviance table for two or more aster model fits.
## S3 method for class 'aster': anova(object, ...)
object, ... |
objects of class "aster" , typically
the result of a call to aster , or a list of
objects of class "aster" for the "asterlist" method. |
Constructs a table having a row for the degrees of freedom and deviance for each model. For all but the first model, the change in degrees of freedom and deviance is also given, as is the corresponding asymptotic P value.
An object of class "anova"
inheriting from class "data.frame"
.
The comparison between two or more models by anova
or
anova.asterlist
will only be valid if they
are (1) fitted to the same dataset,
(2) models are nested, (3) models are of the same type
(all conditional or all unconditional), (4) have the same
dependence graph and exponential families.
None of this is currently checked.
### see package vignette for explanation ### library(aster) data(echinacea) vars <- c("ld02", "ld03", "ld04", "fl02", "fl03", "fl04", "hdct02", "hdct03", "hdct04") redata <- reshape(echinacea, varying = list(vars), direction = "long", timevar = "varb", times = as.factor(vars), v.names = "resp") redata <- data.frame(redata, root = 1) pred <- c(0, 1, 2, 1, 2, 3, 4, 5, 6) fam <- c(1, 1, 1, 1, 1, 1, 3, 3, 3) hdct <- grep("hdct", as.character(redata$varb)) hdct <- is.element(seq(along = redata$varb), hdct) redata <- data.frame(redata, hdct = as.integer(hdct)) aout3 <- aster(resp ~ varb + nsloc + ewloc + pop * hdct, pred, fam, varb, id, root, data = redata) aout4 <- aster(resp ~ varb + nsloc + ewloc + pop * hdct - pop, pred, fam, varb, id, root, data = redata) anova(aout4, aout3)