1、y<-which(A==2)
A[y]<-2001
2、z<-which(A==1)
zz<-which(A!=1)
A[zz]<-"美国"
A[z]<-"中国"

a[a==2]<-2001

a[a==1]<-"中国"

a[a!=1]<-"美国"

为何我用这个程序RCA95_11$cou(RCA95_11$cou== "CHN") <- "中国"
就出现。Error in RCA95_11$cou(RCA95_11$cou == "CHN") <- "中国" :
  invalid function in complex assignment的提示呢？？
也出现了
RCA95_11$cou[RCA95_11$cou== "CHN"] <- "中国"
Warning message:
In `[<-.factor`(`*tmp*`, RCA95_11$cou == "CHN", value = c(1L, 2L,  :
  invalid factor level, NA generated

为何我用这个程序RCA95_11$cou(RCA95_11$cou== "CHN") <- "中国"
就出现。Error in RCA95_11$cou(RCA95_11$cou == "CHN") <- "中国" :
  invalid function in complex assignment的提示呢？？
也出现了
RCA95_11$cou[RCA95_11$cou== "CHN"] <- "中国"
Warning message:
In `[<-.factor`(`*tmp*`, RCA95_11$cou == "CHN", value = c(1L, 2L,  :
  invalid factor level, NA generated

怎么批量可以完成这事呢