I have fitted a survival model in R which is below. However, I am not sure how to make predictions. I tried predicting the survival probability that a patient whose design matrix is
X lives longer than 100 days, but no matter what design matrix I use, the probability is always
0. What do you think I am doing wrong?
library(survival) attach weibull <- survreg(Surv(time,status)~celltype + karno+diagtime+age+prior+trt ,dist="w") beta[,1] <- as.matrix(c(weibull$coef)) x <- as.matrix(c(1,1,0,0,80,10,65,0,2)) #Design matrix lambda <- beta[,1]%*%x 1 - (1 - exp(-lambda*100))