如何在 R 中按列拆分数据框?
r programmingserver side programmingprogramming更新于 2025/6/24 8:22:17
如果数据框中有一列包含重复值或类别，我们可能需要根据该列拆分数据框。
例如，假设有一个名为 df 的数据框，其中包含一列，例如 Col，那么我们可以使用以下命令按 Col 拆分数据框:−
split(df,df$Col)
示例 1
以下代码片段创建了一个示例数据框 −
Group<-sample(c("Male","Female"),20,replace=TRUE)
Score<-rpois(20,8)
df1<-data.frame(Group,Score)
df1
创建以下数据框 −
Group Score 1 Male 8 2 Female 6 3 Female 5 4 Female 7 5 Female 12 6 Female 10 7 Female 9 8 Male 9 9 Male 10 10 Female 13 11 Female 4 12 Male 11 13 Female 5 14 Male 6 15 Female 9 16 Male 9 17 Female 5 18 Female 8 19 Male 3 20 Female 5
要根据 Group 列拆分 df1，请将以下代码添加到上面的代码片段中 −
Group<-sample(c("Male","Female"),20,replace=TRUE)
Score<-rpois(20,8)
df1<-data.frame(Group,Score)
split(df1,df1$Group)
输出
如果将上述所有代码片段作为单个程序执行，则会生成以下输出 −
$Female Group Score 2 Female 6 3 Female 5 4 Female 7 5 Female 12 6 Female 10 7 Female 9 10 Female 13 11 Female 4 13 Female 5 15 Female 9 17 Female 5 18 Female 8 20 Female 5 $Male Group Score 1 Male 8 8 Male 9 9 Male 10 12 Male 11 14 Male 6 16 Male 9 19 Male 3
示例 2
以下代码片段创建了一个示例数据框 −
Class<-sample(c("I","II","III"),20,replace=TRUE)
Number_of_Customers<-sample(1:10,20,replace=TRUE)
df2<-data.frame(Class,Number_of_Customers)
df2
创建以下数据框 −
Class Number_of_Customers 1 II 2 2 I 10 3 III 2 4 III 4 5 III 5 6 III 7 7 III 10 8 II 4 9 II 9 10 I 7 11 III 4 12 I 1 13 I 1 14 I 1 15 III 5 16 II 5 17 II 9 18 II 8 19 II 8 20 I 9
要根据 Class 列拆分 df2，请将以下代码添加到上面的代码片段中 −
Class<-sample(c("I","II","III"),20,replace=TRUE)
Number_of_Customers<-sample(1:10,20,replace=TRUE)
df2<-data.frame(Class,Number_of_Customers)
split(df2,df2$Class)
输出
如果将上述所有代码片段作为单个程序执行，则会生成以下输出 −
$I Class Number_of_Customers 2 I 10 10 I 7 12 I 1 13 I 1 14 I 1 20 I 9 $II Class Number_of_Customers 1 II 2 8 II 4 9 II 9 16 II 5 17 II 9 18 II 8 19 II 8 $III Class Number_of_Customers 3 III 2 4 III 4 5 III 5 6 III 7 7 III 10 11 III 4 15 III 5
