如何根据R中的一个分类列查找多个分类列的唯一值的数量？
要根据一个分类列查找多个分类列的唯一值的数量，我们可以按照以下步骤操作-
首先，创建一个数据框
使用summarise_each函数和n_distinct函数来查找基于分类列的唯一值的数量。
创建数据框
让我们创建一个数据框，如下所示-
x<-
sample(c("First","Second","Third","Fourth","Fifth","Sixth","Seventh","Eighth","Nineth",
"Tenth"),25,replace=TRUE)
C1<-sample(LETTERS[1:4],25,replace=TRUE)
C2<-sample(letters[1:4],25,replace=TRUE)
df<-data.frame(x,C1,C2)
df执行时，上述脚本生成以下内容output(thisoutputwillvaryonyoursystemduetorandomization)-
x C1 C2 1 Seventh B a 2 Third C c 3 Nineth A a 4 Third D c 5 Seventh D d 6 Fourth A c 7 Seventh B a 8 Third D a 9 Seventh D c 10 First A a 11 Eighth D d 12 Tenth C b 13 Fifth A c 14 Second A c 15 Fourth B d 16 Nineth C b 17 Fifth D a 18 First A a 19 Tenth B a 20 Nineth A b 21 Third B b 22 Tenth A a 23 Fifth A a 24 Sixth D b 25 First A c
根据分类列查找唯一值的数量
使用dplyr包的n_distinct函数和summarise_each函数根据x查找C1和C2中唯一值的数量-
x<-
sample(c("First","Second","Third","Fourth","Fifth","Sixth","Seventh","Eighth","Nineth",
"Tenth"),25,replace=TRUE)
C1<-sample(LETTERS[1:4],25,replace=TRUE)
C2<-sample(letters[1:4],25,replace=TRUE)
df<-data.frame(x,C1,C2)
library(dplyr)
df %>% group_by(x) %>% summarise_each(funs(n_distinct(.)))输出
# A tibble: 10 x 3
x C1 C2
1 Eighth 1 1
2 Fifth 2 2
3 First 1 2
4 Fourth 2 2
5 Nineth 2 2
6 Second 1 1
7 Seventh 2 3
8 Sixth 1 1
9 Tenth 3 2
10 Third 3 3