Model.matrix method for coxph models
Reconstruct the model matrix for a cox model.
## S3 method for class 'coxph' model.matrix(object, data=NULL, contrast.arg = object$contrasts, ...)
object |
the result of a |
data |
optional, a data frame from which to obtain the data |
contrast.arg |
optional, a contrasts object describing how factors should be coded |
... |
other possible argument to |
When there is a data argument this function differs from most
of the other model.matrix methods in that the response variable
for the original formula is not required to be in the data.
If the data frame contains a terms attribute then it is
assumed to be the result of a call to model.frame, otherwise
a call to model.frame is applied with the data as an argument.
The model matrix for the fit
Terry Therneau
fit1 <- coxph(Surv(time, status) ~ age + factor(ph.ecog), data=lung)
xfit <- model.matrix(fit1)
fit2 <- coxph(Surv(time, status) ~ age + factor(ph.ecog), data=lung,
x=TRUE)
all.equal(model.matrix(fit1), fit2$x)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.