R: Update method for a 'xtabs' object

update.xtabs {vcdExtra} | R Documentation

## Update method for a `xtabs` object

### Description

Provides an `update` method for `"xtabs"` objects, typically by removing terms from the formula to collapse over them.

### Usage

    ## S3 method for class 'xtabs'
    update(object, formula., ..., evaluate = TRUE)

### Arguments

`object` | An existing `"xtabs"` object
`formula.` | Changes to the formula ? see `update.formula` for details
`...` | Additional arguments to the call, or arguments with changed values.
`evaluate` | If `TRUE`, evaluate the new call else return the call

### Value

If `evaluate == TRUE`, the new `"xtabs"` object, otherwise the updated call

### Author(s)

Michael Friendly

### See Also

`update.formula` for details on updates to model formulae

`margin.table` does something similar, `collapse.table` collapses category levels

### Examples

    vietnam.tab <- xtabs(Freq ~ sex + year + response, data=Vietnam)

    update(vietnam.tab, formula = ~ . -year)

[Package vcdExtra version 0.7-1 Index]