R語言中根據日期篩選數據
1、測試數據
manager <- 1:5 date <- c("10/24/08","10/28/08","10/1/08","10/12/08","5/1/09") country <- c("US","US","UK","UK","UK") gender <- c("M","F","F","M","F") age <- c(32,45,25,39,99) q1 <- c(5,3,3,3,2) q2 <- c(4,5,5,3,2) q3 <- c(5,2,5,4,1) q4 <- c(5,5,5,NA,2) q5 <- c(5,5,2,NA,1) leadership <- data.frame(manager,date,country,gender,age,q1,q2,q3,q4,q5, stringsAsFactors = F) leadership$age[leadership$age == 99] <- NA leadership <- within(leadership,{ agecat = NA agecat[age > 75] <- "Elder" agecat[age >= 55 & age <= 75] <- "Middle age" agecat[age < 55] <- "Young" }) leadership
2、依據第二列篩選2008.10.5到2008.10.25的數據
leadership$date <- as.Date(leadership$date, "%m/%d/%y") leadership startday <- as.Date("2008-10-05") endday <- as.Date("2008-10-25") new<-leadership[which(leadership$date >= startday & leadership$date <= endday),] new
