| update.xtabs {vcdExtra} | R Documentation |
xtabs object
Provides an update method for "xtabs" objects,
typically by removing terms from the formula to collapse over them.
## S3 method for class 'xtabs' update(object, formula., ..., evaluate = TRUE)
object |
An existing |
formula. |
Changes to the formula ? see |
... |
Additional arguments to the call, or arguments with changed values. |
evaluate |
If |
If evaluate == TRUE, the new "xtabs" object, otherwise the updated call
Michael Friendly
update.formula for details on updates to model formulae
margin.table does something similar,
collapse.table collapses category levels
vietnam.tab <- xtabs(Freq ~ sex + year + response, data=Vietnam) update(vietnam.tab, formula = ~ . -year)