Proportional Hazards Regression Object
This class of objects is returned by the
coxph class of functions
to represent a fitted proportional hazards model.
Objects of this class have methods for the functions
the vector of coefficients. If the model is over-determined there will be missing values in the vector corresponding to the redundant columns in the model matrix.
the variance matrix of the coefficients. Rows and columns corresponding to any missing coefficients are set to zero.
this component will be present only if the
robustoption was true. If so, the
varcomponent will contain the robust estimate of variance, and this component will contain the ordinary estimate.
a vector of length 2 containing the log-likelihood with the initial values and with the final values of the coefficients.
value of the efficient score test, at the initial value of the coefficients.
the robust log-rank statistic, if a robust variance was requested.
the Wald test of whether the final coefficients differ from the initial values.
number of iterations used.
the vector of linear predictors, one per subject. Note that this vector has been centered, see
predict.coxphfor more details.
the martingale residuals.
vector of column means of the X matrix. Subsequent survival curves are adjusted to this value.
the number of observations used in the fit.
the number of events (usually deaths) used in the fit.
a vector of length 6, containing the number of pairs that are concordant, discordant, tied on x, tied on y, and tied on both, followed by the standard error of the concordance statistic.
the first derivative vector at the solution.
the vector of case weights, if one was used.
the method used for handling tied survival times.
the na.action attribute, if any, that was returned by the
the value of the timefix option used in the fit
The object will also contain the following, for documentation see the
call, and, optionally,
The following components must be included in a legitimate