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

From: Spencer Graves <spencer.graves_at_pdf.com>
Date: Mon 28 Mar 2005 - 13:35:49 EST

      What operating system and which version of R?

      I got a similar error message under R 2.0.1 under Windows 2000:

 > y <- scan(file = x[1])
Error in scan(file = x[1]) : "scan" expected a real, got "ࡱ"

      Part of the function definition for "scan" is 'scan(file = "", what = double(0), ...'. This means that by default, "scan" was expecting double precision numbers. When it found an unrecognizable binary, it complained. Using 'what="raw"' produced something:

 > y <- scan(file = x[1], what="raw")
Read 1 items

      The file x[1] was an MS Word *.wbk file, and scan was only able to read a portion of the header using "raw".

      Have you considered "try"?

 > y <- try(scan(file=x[1]))
Error in scan(file = x[1]) : "scan" expected a real, got "ࡱ"  > y
[1] "Error in scan(file = x[1]) : \"scan\" expected a real, got \"\021\261\"\n"
attr(,"class")
[1] "try-error"

       What are you trying to do? The following worked for me just now?

 > write(pi, "pi.txt")
 > scan('pi.txt')
Read 1 items
[1] 3.141593
 > all.equal(scan('pi.txt'), pi)
Read 1 items
[1] "Mean relative difference: 1.102658e-07"

      hope this helps. spencer graves

Andrew Peterson wrote:

>Hi, can anyone please tell me if it is possible to use
>a variable to pass a file name to scan()?
>
>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>"
>
>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.
>
>______________________________________________
>R-help@stat.math.ethz.ch mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
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>
>



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Mon Mar 28 13:44:29 2005

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