在R中记录变量时出错

我从Excel导入了一个文件，该文件在导入后具有以下属性：

str(mydata)
$ Injury   : chr  "MMCAI" "MMCAI" "MMCAI" "MMCAI" ...
$ Na_RR    : num  161 152 152 150 143 ...
$ place    : chr  "core" "core" "core" "core" ...

现在我想创建5个不同的组，结合内翻损伤和位置 我有这个密码

mydata$group[mydata$Injury=="MMCAI" & mydata$place=="core"]<- "IC"

我找不到错误。。。 任何帮助都将不胜感激

---

谢谢

如果相关变量有前置/后置空格，则可能发生这种情况

 mydata$group[with(mydata, Injury=='MMCAI' & place=='core')] <- 'IC'
 mydata
 #   Na_RR place  Injury group
 #1   231  core   MMCAI    IC
 #2   232  core  MMCAI   <NA>
 #3   233  core   MMCAI  <NA>
 #4   234  core  MMCAI   <NA>
 #5   235  core   MMCAI  <NA>
 #6   239  core   MMCPI  <NA>

---

嗨，阿克伦。谢谢！使用“stringr”包的代码仅使用mydata$place就可以很好地工作

 mydata$group[with(mydata, Injury=='MMCAI' & place=='core')] <- 'IC'
 mydata
 #   Na_RR place  Injury group
 #1   231  core   MMCAI    IC
 #2   232  core  MMCAI   <NA>
 #3   233  core   MMCAI  <NA>
 #4   234  core  MMCAI   <NA>
 #5   235  core   MMCAI  <NA>
 #6   239  core   MMCPI  <NA>

library(stringr)
mydata[c('place', 'Injury')] <- lapply(mydata[c('place', 'Injury')], str_trim)
mydata$group[with(mydata, Injury=='MMCAI' & place=='core')] <- 'IC'
mydata
#  Na_RR place Injury group
#1   231  core  MMCAI    IC
#2   232  core  MMCAI    IC
#3   233  core  MMCAI    IC
#4   234  core  MMCAI    IC
#5   235  core  MMCAI    IC
#6   239  core  MMCPI  <NA>

mydata <- structure(list(Na_RR = c(231L, 232L, 233L, 234L, 235L,
 239L), 
place = c("core", "core", "core", "core", "core", "core"), 
Injury = c("MMCAI", "MMCAI ", " MMCAI", " MMCAI ", " MMCAI", 
"MMCPI")), .Names = c("Na_RR", "place", "Injury"),
row.names = c(NA,-6L), class = "data.frame")