library(survival) # # The constuction of a survival curve with sparse frailties # # In this case the coefficient vector is kept in two parts, the # fixed coefs and the (often very large) random effects coefficients # The survfit function treats the second set of coefficients as fixed # values, to avoid an unmanagable variance matrix, and behaves like # the second fit below. fit1 <- coxph(Surv(time, status) ~ age + frailty(inst), lung) sfit1 <- survfit(fit1) # A parallel model with the frailties treated as fixed offsets offvar <- fit1$frail[as.numeric(factor(lung$inst))] fit2 <- coxph(Surv(time, status) ~ age + offset(offvar),lung) fit2$var <- fit1$var #force variances to match all.equal(fit1$coef, fit2$coef) sfit2 <- survfit(fit2, newdata=list(age=fit1$means, offvar=0)) all.equal(sfit1$surv, sfit2$surv, tol=1e-7) all.equal(sfit1$var, sfit2$var)
Any scripts or data that you put into this service are public.
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.