如何為給定數據框填充R中缺少的數據點

Question

我有一個包含日期，產品和金額的數據框。 但是產品b並非在每個日期都有效，我希望它的NA或余額為0。 這可能嗎？

Summary_Date <- 
  as.Date(c("2017-01-31",
        "2017-02-28",
        "2017-03-31",
        "2017-03-31",
        "2017-04-30",
        "2017-05-31",
        "2017-05-31",
        "2017-06-30"))
Product <-
  as.character(c("a","a","a","b","a","a","b","a"))
Amounts <-
  as.numeric(c(10,10,10,20,10,10,20,10))

df <- data.frame(Summary_Date,Product,Amounts)

問候，阿克塞爾

Answer 1

您可以使用tidyr ：

> library(tidyr)
> complete(data = df,Summary_Date,Product)
# A tibble: 12 x 3
   Summary_Date Product Amounts
         <date>  <fctr>   <dbl>
 1   2017-01-31       a      10
 2   2017-01-31       b      NA
 3   2017-02-28       a      10
 4   2017-02-28       b      NA
 5   2017-03-31       a      10
 6   2017-03-31       b      20
 7   2017-04-30       a      10
 8   2017-04-30       b      NA
 9   2017-05-31       a      10
10   2017-05-31       b      20
11   2017-06-30       a      10
12   2017-06-30       b      NA