Schoenfeld function
= Schoenfeld function
{c}
{title2=$s_j(\beta)=z_{i_j}-\bar z(\beta,t_j)$}
At a distinct event time, the Schoenfeld function is the event subject's covariate minus the hazard-weighted covariate mean over the <risk set>, as a function of a trial coefficient $\beta$. Its evaluation at the fitted coefficient is a <Schoenfeld residual>. The sum of these functions is the <Cox partial likelihood> <score function>, and each is conditionally centered at zero at the true proportional-hazards coefficient.