testFrame <- data.frame(First=sample(1:10, 20, replace=T),

Second=sample(1:20, 20, replace=T), Third=sample(1:10, 20, replace=T),

Fourth=rep(c(“Alice”,“Bob”,“Charlie”,“David”), 5),

Fifth=rep(c(“Edward”,“Frank”,“Georgia”,“Hank”,“Isaac”),4))

basically I can go with:

1, model.matrix(~ 0+First + Second + Third + Fourth + Fifth, data=testFrame)

2, model.matrix(~ First + Second + Third + Fourth + Fifth, data=testFrame)

Since coxph does not have intercept, should I go with matrix 1? Or should I still feed the stan survival model with the most commonly used matrix 2?

Thank you for your advice in advance.