R help - Sep 2009 - Skipping missing files when importing data

Trying to import a bunch of data files named like f001, f002, ....f999. Some of
the files may be
missing and the missing files vary from time to time.

Used for loop and read.table. When it reaches the missing file (say f100), it
shows:

Error in file(file, "r") : cannot open the connection
In addition: Warning message:
In file(file, "r") :
  cannot open file 'f100': No such file or directory

and the program stops.

How can I skip the missing ones and keep the program running? Guess either
checking the validity of
filenames, or ignore the error message may work. Which functions should be used
or any better ideas?


-RJ

Try ?file.exists.

if (file.exists(fxxx)) {
  read.table(fxxx)
} else {
  cat("\"", fxxx, "\" is missing\n", sep =
"")
}

HTH,

--sundar

On Sun, Sep 20, 2009 at 9:28 PM, jiangrm <jiangrm at gmail.com>
wrote:
> Trying to import a bunch of data files named like f001, f002, ....f999.
Some of the files may be
> missing and the missing files vary from time to time.
>
> Used for loop and read.table. When it reaches the missing file (say f100),
it shows:
>
> Error in file(file, "r") : cannot open the connection
> In addition: Warning message:
> In file(file, "r") :
> ?cannot open file 'f100': No such file or directory
>
> and the program stops.
>
> How can I skip the missing ones and keep the program running? Guess either
checking the validity of
> filenames, or ignore the error message may work. Which functions should be
used or any better ideas?
>
>
> -RJ
>
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