如何将完全匹配从数据B复制到r中的数据A.

Question

假设我有两个数据框A和B.

A

 products Color  price
 banana   Yellow  NA
 Apple    Red     NA
 Avocado  Green   NA
 Apricot  Yellow  NA

乙

products Color  price
  banana   Yellow  2.5
  Apple    Red     3.0
  Avocado  Green   4.0
  Apricot  Yellow  NA

我的问题是从数据A中获取产品价格的最快方法是什么，并将其保存在数据B中，因此结果将是这样的

乙

viewWillAppear

Answer 1

如果B和A中的产品之间的唯一区别是大写，那么您可以使用以下内容：

A = data.frame(products = c("apple", "orange", "avocado", "banana", "blueberry"),
           price = c(3.0, 2.5, 4.0, 2.5, 1.5))

B = data.frame(products = c("banana", "Apple", "Avocado", "Apricot"),
           color = c("Yellow", "Red", "Green", "Yellow"),
           price = c(NA, NA, NA, NA))

for (i in 1:nrow(B)) {
   B$price[i] =  A$price[match(tolower(B$products[i]), A$products)]
}