在R中修改字符串

我将如何更改这些字符串以删除前的所有字符。并替换为每个的第一个字母

例如，让Alexander.Mattison变成A.Mattison等等

谢谢你抽出时间

数据如下

> dput(rb2019capa)
structure(list(rusher_player_name = c("Aaron.Jones", "Adrian.Peterson", 
"Alexander.Mattison", "Alvin.Kamara", "Austin.Ekeler", "Brian.Hill"
), Team = c("Packers", "Redskins", "Vikings", "Saints", "Chargers", 
"Falcons"), `Salary Cap Value` = c(695487, 1780000, 700545, 1050693, 
646668, 645000), `Cash Spent` = c(645000, 2530000, 1317180, 807500, 
645000, 645000)), spec = structure(list(cols = list(Player = structure(list(), class = c("collector_character", 
"collector")), Team = structure(list(), class = c("collector_character", 
"collector")), `Salary Cap Value` = structure(list(), class = c("collector_number", 
"collector")), `Cash Spent` = structure(list(), class = c("collector_number", 
"collector"))), default = structure(list(), class = c("collector_guess", 
"collector")), skip = 1), class = "col_spec"), row.names = c(1L, 
4L, 6L, 7L, 10L, 16L), class = c("spec_tbl_df", "tbl_df", "tbl", 
"data.frame"))

---

我们可以使用

sub

提取第一个字符和

“

之后的所有内容

---

这有什么不同。请不要重复邮寄。人们对你上一篇试图提供帮助的帖子发表了评论。编辑上一个问题，而不是重新发布一个几乎相同的问题。。理解

sub("(.).*\\.(.*)", "\\1.\\2", rb2019capa$rusher_player_name)
#[1] "A.Jones"    "A.Peterson" "A.Mattison" "A.Kamara"   "A.Ekeler"   "B.Hill"