attrassign {survival} | R Documentation

## Create new-style "assign" attribute

### Description

The `"assign"` attribute on model matrices describes which columns come from which terms in the model formula. It has two version. R uses the original version, but the newer version is sometimes useful.

### Usage

    ## Default S3 method:
    attrassign(object, tt,...)
    ## S3 method for class 'lm':
    attrassign(object,...)

### Arguments

`object` | model matrix or linear model object
`tt` | terms object
`...` | ignored

### Value

A list with names corresponding to the term names and elements that are vectors indicating which columns come from which terms

### See Also

`terms`,`model.matrix`

### Examples

    formula<-Surv(time,status)~factor(edtrt)
    tt<-terms(formula)
    mf<-model.frame(tt,data=pbc)
    mm<-model.matrix(tt,mf)
    ## a few rows of data
    mm[1:3,]
    ## old-style assign attribute
    attr(mm,"assign")
    ## new-style assign attribute
    attrassign(mm,tt)

[Package survival version 2.18 Index]