search for: date30

..., 1L)), .Names = c("ID", "Date","event"), class = "data.frame", row.names = c(NA, 14L)) ##     remove non events data2 <- data1[data1$event==1,] library(doBy) ##     create a table of first events step1 <- summaryBy(Date~ID, data = data2, FUN=min) step1$Date30 <- step1$Date.min+30                                     step2 <- merge(data2, step1, by.x="ID", by.y="ID") ##     use an ifelse to essentially remove any events that shouldn't be counted step2$event <- ifelse(as.numeric(step2$Date) >= step2$Date.min & as.nu...