model.matrix.coxph {survival}R Documentation

Model.matrix method for coxph models

Description

Reconstruct the model matrix for a cox model.

Usage

## S3 method for class 'coxph':
model.matrix(object, data, contrast.arg = object$contrasts, ...)

Arguments

object the result of a coxph model
data optional, a data frame from which to obtain the data
contrast.arg optional, a contrasts object describing how factors should be coded
... other possible argument to model.frame

Details

for details see the documentation of the generic method.

Value

The model matrix for the fit

Author(s)

Terry Therneau

See Also

model.matrix

Examples

fit1 <- coxph(Surv(time, status) ~ age + factor(ph.ecog), data=lung)
linear.predictor <- model.matrix(fit1) 

fit2 <- coxph(Surv(time, status) ~ age + factor(ph.ecog), data=lung,
                                 x=TRUE)
all.equal(model.matrix(fit1), fit2$x)

[Package survival version 2.35-8 Index]