Hi, I have collected data in order to generate a Kaplan Meier Plot (survival curve). However the data does not measure events for individuals but for the whole group. e.g. day living deaths group 2 16 5 A 2 12 2 B 3 11 0 A 3 10 3 B Can the survival package do something with this data directly or do I have to generate a different format first. Thanks Ido