使用dplyr比较两个字符列的内容

Question

我试图比较一列的内容是否与另一列的内容相同或不同。

Response <- c("Old", "New", "Old", "New")
Correct_answer <- c("New", "Old", "Old", "New")
comparison <- data.frame(Response, Correct_answer)

我试过了：

mutate(comparison, Resp_final = ifelse(grepl("Old", Response), "1",
                                  ifelse(grepl("New", Response), "2", "")))

但它只检查“响应”列。如何比较“Response”和“Correct_answer”列并使用dplyr将结果输入一列？

谢谢！

Answer 1

如果您唯一关心的是平等，那么简单的if_else将会：

comparison %>% mutate(Resp_final = if_else(Response == Correct_answer, 1, 0))

但是如果你想比较它们是否相等而且如何它们是相等的，你可以用case_when来做到这一点：

comparison %>% 
  mutate(Resp_final = case_when(
   Response == Correct_answer & Response == "Old" ~ "1",
   Response == Correct_answer & Response == "New" ~ "2",
   TRUE                                           ~ ""))

输出：

## Response Correct_answer resp_final
## 1        Old            New           
## 2        New            Old           
## 3        Old            Old          1
## 4        New            New          2