08/08/11 23:12:14
> z <- c(120,201,150,96,115)
> z[z>=150] <- "C"
> z[z>=100 & z<150] <- "B"
> z[z<100] <- "A"
> z
[1] "B" "C" "C" "96" "B"
?????どうしてうまくいかない？？？
逆では？？ うまくいかない？？
> z <- c(120,201,150,96,115)
> z[z<100] <- "A"
> z
[1] "120" "201" "150" "A" "115"
> z[z>=100 & z<150] <- "B"
> z
[1] "B" "201" "150" "A" "B"
> z[z>=150] <- "C"
> z
[1] "C" "C" "C" "C" "C"
なぜなのか教えて