如何在R中的data.table对象中将多个字符串列的第一个字母转换为大写？
要将多个字符串列的第一个字母转换为data.tableR中对象中的大写，我们可以按照以下步骤操作-
首先，创建一个data.table带有字符串列的对象。
然后，使用sub函数和dplyr包的mutate_each函数将字符串列中的第一个字母转换为大写。
示例
创建data.table对象
让我们创建一个data.table对象，如下所示-
library(data.table)
Names<-
sample(c("rahul","rosy","hidayah","seema","john","sarbat","shaun","sam","teena","ila"," kunal"),25,replace=TRUE)
Level<-sample(c("low","medium","high"),25,replace=TRUE)
DT<-data.table(Names,Level)
DT输出结果执行时，上述脚本生成以下内容output(thisoutputwillvaryonyoursystemduetorandomization)-
Names Level
1: seema high
2: john low
3: rahul low
4: kunal medium
5: shaun medium
6: john low
7: kunal medium
8: ila high
9: sam low
10: rosy medium
11: seema medium
12: ila medium
13: kunal medium
14: sarbat high
15: shaun low
16: sarbat high
17: ila medium
18: john high
19: sarbat medium
20: rahul low
21: sam low
22: teena low
23: john high
24: john low
25: ila medium
Names Level将多列中的第一个字母转换为大写
使用sub函数和dplyr包的mutate_each函数将Names和Level列中的第一个字母转换为大写-
library(data.table)
Names<-
sample(c("rahul","rosy","hidayah","seema","john","sarbat","shaun","sam","teena","ila","kunal"),25,replace=TRUE)
Level<-sample(c("low","medium","high"),25,replace=TRUE)
DT<-data.table(Names,Level)
library(dplyr)
DT %>% mutate_each(funs(sub("(.)","\\U\\1", ., perl=TRUE)))输出结果Names Level 1: Seema High 2: John Low 3: Rahul Low 4: Kunal Medium 5: Shaun Medium 6: John Low 7: Kunal Medium 8: Ila High 9: Sam Low 10: Rosy Medium 11: Seema Medium 12: Ila Medium 13: Kunal Medium 14: Sarbat High 15: Shaun Low 16: Sarbat High 17: Ila Medium 18: John High 19: Sarbat Medium 20: Rahul Low 21: Sam Low 22: Teena Low 23: John High 24: John Low 25: Ila Medium Names Level