Question

我在R schools中有数据有94个变量。其中我在一组中选择了3个变量进行分析：

schools_set <- data.frame(schools$Schoolname, schools$SchoolGenderID, and School$)

SchoolGenderID按列分列（1s和2s）1为男性，2为女性。我的问题是，如何在同一数据框内的变量"Male"中分别用"Female"和schools$SchoolGenderID替换这些1和2？

Answer 1

schools$SchoolGenderID[schools$SchoolGenderID == 1] <- "Male"
schools$SchoolGenderID[schools$SchoolGenderID == 2] <- "Female"

或者

schools$SchoolGenderID <- ifelse(schools$SchoolGenderID == 1, "Male", "Female")

在这种特殊情况下推荐后者。

Answer 2

尝试data.table方式：）

schools = data.table (schools)

schools [ SchoolGenderID == "Male", "SchoolGenderID" := "1"]
schools [ SchoolGenderID == "Female", "SchoolGenderID" := "2"]
schools = schools [order (Schoolname, SchoolGenderID)]

结果性别列不是数字，而是字符类型，因为初始列是字符类型。如果需要数字列，请创建新列：

schools [ SchoolGenderID == "Male", "SchoolGenderNo" := 1]
schools [ SchoolGenderID == "Female", "SchoolGenderNo" := 2]

Answer 3

这是dplyr

中的一种方式

library(tidyverse)


schools_set <- schools %>%
                 select(Schoolname, SchoolGenderID) %>% # Make your subset 
                 mutate(
                   school_gender_id = ifelse(SchoolGenderID == 1, 
                                              "Male", "Female")
                 ) %>% 
                 mutate(
                   school_gender_id = as.factor(school_gender_id)
                 ) %>%
                 arrange(school_gender_id) # Order dataframe

mutate允许您修改变量并创建新变量。安排做秩序的工作。如果订单不正确，您可以执行以下操作：arrange(desc(school_gender_id))。 %>%被称为“管道”，意思是“在执行此操作后，转到下一个命令。”

我推荐这个教程：http://r4ds.had.co.nz/introduction.html 它是由R的创建者Hadley Wickham编写的。非常完整和有用的R编程简介。如果你学习tidyverse

，那将会更容易，也不那么特别。

替换变量中的值

3 个答案: