[R] Converting character strings to numeric

[Mulholland, Tom]

I assume that I have missed something fundamental and that it is there in front of me in "An Introduction to R", but I need someone to point me in the right direction.

> x1 <- "1159 1129 1124 -5 -0.44 -1.52"
> x2 <- c("1159","1129","1124","-5","-0.44","-1.52")
> x3 <- unlist(strsplit(x1," "))
> 
> 
> str(x2)
 chr [1:6] "1159" "1129" "1124" "-5" "-0.44" "-1.52"
> str(x3)
 chr [1:6] "1159" "1129" "1124" "-5" "-0.44" "-1.52"
> 
> as.numeric(x2)
[1] 1159.00 1129.00 1124.00   -5.00   -0.44   -1.52
> as.numeric(x3)
[1] 1159 1129 1124   NA   NA   NA
Warning message:
NAs introduced by coercion 

What do I have to do to get x3  to be the same as x2. 

Tom