[R] Can I use a variable to pass a file name to scan() ?

[Uwe Ligges]

Andrew Peterson wrote:

> Hi, can anyone please tell me if it is possible to use
> a variable to pass a file name to scan()?

Yes.

> I am trying to write a program that loops through a
> series of text files. I use list.files() to create a
> character vector of file names. Then I would like to
> take  one string at a time from the character vector
> and use that string to specify the name of the text
> file I want to open using scan().
> 
> I have used constructs such as
> 
> x <- list.files()
> 
> y <- scan(file = x[1])
> 
> but I always get the following error message:
> 
> Error in scan(file = x[1]) : "scan" expected a real,
> got "<CLOSE>"

Right, the file named in x[1] is a text file that starts with "<CLOSE>" 
which is not a number (and scan expects a number, by default), hence 
scan complains.

Use
    y <- scan(file = x[1], what="character")
and you will see that it works.

Uwe Ligges


> I've read all the documentation at least a couple of
> times and have searched this list to no avail. Any
> help would be greatly appreciated!
> 
> Thanks,
> 
> Andrew.
> 
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