Question

数据集wineData包含一个名为quality的属性，数值范围从1到8.我试图通过以下代码对其进行分类：

wineData$taste <- NA
wineData$taste[which(wineData$quality< 6)] <- bad
wineData$taste[which(wineData$quality>6)] <- excellent
wineData$taste[which(wineData$quality=6)] <- normal
wineData$taste <- factor(wineData$taste)
wineData`

这里只有质量＆gt; 6被归类为优秀，其他所有被归类为NA。为什么它无法对其他人进行分类？

这些是我得到的错误。

wineData $ taste [wine（wineData $ quality＆gt; 6）]＆lt; - 优秀错误：对象＆＃39;优秀＆＃39;未找到 wineData $ taste [which（wineData $ quality == 6）]＆lt; - normal Error：object＆＃39; normal＆＃39;找不到

Answer 1

这样做

wineData$taste <- NA
    wineData$taste[which(wineData$quality< 6)] <- "bad"
    wineData$taste[which(wineData$quality>6)] <- "excellent"
    wineData$taste[which(wineData$quality==6)] <- "normal"
    wineData$taste <- factor(wineData$taste)
    wineData

Answer 2

您也可以使用dplyr::case_when()

library(dplyr)
wineData <- wineData %>%
  mutate(
    taste = case_when(
      quality < 6 ~ "bad",
      quality > 6 ~ "excellent",
      quality = 6 ~ "normal",
      TRUE        ~  NA
    ),
    taste = as.factor(taste, levels = c("bad", "normal", "excellent")
  )

R编程，对数据进行分类

2 个答案: