add1drop1 {gRc}R Documentation

Add or drop colour classes to RCOX models

Description

Make a test for adding/dropping all colour classes in scope for an RCOX model.

Usage

## S3 method for class 'rcox':
add1(object, scope, details = 0, trace = 0, ...)
## S3 method for class 'rcox':
drop1(object, scope, details = 0, trace = 0, stat = "wald", ...) 

Arguments

object An RCOX model, an object of class 'rcox'
scope A set of edge colour classes to be considered for addition or deletion, see 'details'.
details Control the amount of output created.
trace For debugging purposes
stat Either "wald" for a Wald statistic or "dev" for a deviance statistic.
... Additional arguments, currently unused.

Value

A list with entries:

tab A data frame with the test results
cc A list of colour classes

Note

Note that the keyword 'stat' is not available for add1 because this function expands the current model and hence the Wald statistic is not available.

Author(s)

Søren Højsgaard, sorenh@agrsci.dk

See Also

comparecc, stepadd1, stepdrop1

Examples

data(math)
gc.sat <- ~me:ve:al:st:an
gc.1   <- ~me+ve+al+st+an

m.sat <- rcox(gm=gc.sat, data=math)
m.1   <- rcox(gm=gc.1,   data=math)

t.sat <- drop1(m.sat)
t.sat$tab
t.sat$cc

t.1   <- add1(m.1)
t.1$tab
t.1$cc

[Package gRc version 0.2.2 Index]