These are the the functions called by coxph that do the actual
computation.
In certain situations, e.g. a simulation, it may be advantageous to
call these directly rather than the usual coxph
call using
a model formula.
agreg.fit(x, y, strata, offset, init, control, weights, method,
rownames, resid=TRUE, nocenter=NULL)
coxph.fit(x, y, strata, offset, init, control, weights, method,
rownames, resid=TRUE, nocenter=NULL)
Matix of predictors. This should not include an intercept.
a Surv
object containing either 2 columns (coxph.fit)
or 3 columns (agreg.fit).
a vector containing the stratification, or NULL
optional offset vector
initial values for the coefficients
the result of a call to coxph.control
optional vector of weights
method for hanling ties, one of "breslow" or "efron"
this is only needed for a NULL model, in which case it contains the rownames (if any) of the original data.
compute and return residuals.
an optional list of values. Any column of the X matrix whose values lie strictly within that set will not be recentered. Note that the coxph function has (-1, 0, 1) as the default.
a list containing results of the fit
This routine does no checking that arguments are the proper length or type. Only use it if you know what you are doing!
The resid
and concordance
arguments will save some compute
time for calling routines that only need the likelihood,
the generation of a permutation distribution for instance.