[R] Using a sting in variable names

[Ken]

olafgy <olafgy <at> gmail.com> writes:

> 
> Hi there,
> 
> I am trying to import 100 files with the names of "vpn 1 .dat" to "vpn 100
> .dat"
> into a respective table calld vpn1 to vpn100.
> 
> I therfore have created a variable X<-1:100
> 
> I not want to use X as a subtitute for the number in my filename, so that I
> have to write only one function and it does the operation with all files.
> 
> I have tried every combination i could imagine to include the string X into
> the file name:
> 
> vpn'X'  , vpn"X"  , vpn[X] ,  and so on, but R never did what I wanted it
> too.
> 
> vpn"X"<-read.table("vpn "X" .dat")
> 
> So is there a way to do this in R??? or should I use an intirely new
> aproach?
> 
> Thanks for your Help!
> 
> --
> View this message in context:
http://r.789695.n4.nabble.com/Using-a-sting-in-variable-names-tp3527318p3527318.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> 

why don't you use a list (?list)?  This is particularly useful if each file is
formatted in the same way (ie. if they have the same columns, in the same order,
etc.), but this is not a necessity. 

Read each file as an separate item in the list.  That way if you want to compute
the same statistic on each of your files, you can use lapply on the each item of
the list.  I think this way save memory, but not totally sure on it.

Example:
X <- 1:100
vpn <- vector(mode = "list", length = length(X))

for(i in 1:length(X)){
vpn[[i]] <- read.table(paste("vpn", X[i], ".dat", sep =""))
}

HTH,
Ken