R语言中subset函数的用法

 

1、 测试数据

> df <- data.frame(Age=c(22,24,25,26), Gender=c("Girl","Girl","Boy","Boy"),
+                City=c("Shanghai","Beijing","Guangzhou","Nanjing"))
> df
  Age Gender      City
1  22   Girl  Shanghai
2  24   Girl   Beijing
3  25    Boy Guangzhou
4  26    Boy   Nanjing

 

2、依据单列过滤数据

> df
  Age Gender      City
1  22   Girl  Shanghai
2  24   Girl   Beijing
3  25    Boy Guangzhou
4  26    Boy   Nanjing
> subset(df, Age > 24)         ## 依据Age过滤数据
  Age Gender      City
3  25    Boy Guangzhou
4  26    Boy   Nanjing

 

3、依据多列同时过滤数据

> df
  Age Gender      City
1  22   Girl  Shanghai
2  24   Girl   Beijing
3  25    Boy Guangzhou
4  26    Boy   Nanjing
> subset(df,Age <= 25 )
  Age Gender      City
1  22   Girl  Shanghai
2  24   Girl   Beijing
3  25    Boy Guangzhou
> subset(df,Age <= 25 & Gender == "Girl")   ## 指定多列条件进行数据过滤
  Age Gender     City
1  22   Girl Shanghai
2  24   Girl  Beijing

 

4、依据列筛选的同时，指定要提取的列

> df
  Age Gender      City
1  22   Girl  Shanghai
2  24   Girl   Beijing
3  25    Boy Guangzhou
4  26    Boy   Nanjing
> subset(df, Gender == "Girl", select = c("Age","City"))     ## 依据gender多虑数据， 同时指定要提取的列
  Age     City
1  22 Shanghai
2  24  Beijing

 

来源：https://blog.csdn.net/qq_42458954/article/details/81198729