search for: dateofdeath

...#39;s quite hard for me to resolve. I have a database containing data of a clinical trial in which patients are included that survived or died: x <- matrix(data=c(1:5,0, "1/1/2012 00:00:00",0,0,"1/7/2012 00:00:00"), nrow=5, ncol=2, dimnames= list(NULL,c("ID", "dateofdeath"))) My file is a .csv so I don't have a problem with the brackets, don't know how to show you the idea without the brackets... I want to be able to do calculations with the values in the column x$dateofdeath so use the chron-package for this: library(chron) x$dateofdeath<- as.cha...