[R] Converting characters to numbers in data frames

[Peter Wolf]

Try:

NAMES=c("NRes.1.2.", "NRes.1.3.", "NRes.1.4.", "NRes.1.5.", "NRes.1.6.")
pattern<-"NRes\.([0-9]*)\.([0-9]*)\."
data.frame(x=sub(pattern,"\\1",NAMES),y=sub(pattern,"\\2",NAMES))

@
output-start
Thu Aug 25 14:08:50 2005
  x y
1 1 2
2 1 3
3 1 4
4 1 5
5 1 6
output-end

Peter Wolf

Anon. wrote:
>I'm sure I'm missing something obvious here, but I can't find the 
>solution (including in the FAQ etc.).
>
>I have a vector of names of variables like this: NRes.x.y. where x and y 
>are numbers.  I want to extract these numbers as numbers to use 
>elsewhere.  I can extract the numbers as a list of characters using 
>strsplit(), and convert that to a data frame, e.g.:
>
>NAMES=c("NRes.1.2.", "NRes.1.3.", "NRes.1.4.", "NRes.1.5.", "NRes.1.6.")
>NUMBERS=strsplit(gsub("NRes.","", NAMES, perl =T), '.', fixed = TRUE)
>NUMBERS.df=t(data.frame(NUMBERS))
>
>But I now want to convert the characters to be numeric.  Using 
>as.numeric(NUMBERS.df) converts them, but to a vector.  How can I 
>convert and keep as a data frame?  I could use this:
>
>matrix(as.numeric(NUMBERS.df), ncol=dim(NUMBERS.df)[2])
>
>but I seem to be jumping through far too many hoops: there must be an 
>easier way.  An suggestions?
>
>Bob
>
>