如何在R中按行和列匯總數據

Question

我有以下問題。 我有一個數據表如下：

並希望創建一個如下所示的摘要：

在 Excel 中，簡單的數據透視表很重要，但如何在 R 中做到這一點？

Answer 1

library(dplyr)
cardata <- data.frame(country = c("poland", "germany", "austria",
                              "poland","poland", "austria",
                              "germany","germany"),
                  car = c("Fiat", "Fiat", "BMW", "Fiat", "BMW",
                          "Toyota", "Toyota", "Toyota"),
                  Age = c(5, 4, 2, 6, 6, 2, 1, 8),
                  Km = c(12e4, 10e4, 22e3, 14e4, 15e4, 52e3, 21e3, 22e4))

cardata %>%
group_by(country, car) %>%
summarise(AvgAge = mean(Age),
          AvgKm = mean(Km))