[R] Globbing Files in R

[Duncan Murdoch]

On 12/22/2008 1:14 PM, Earl F Glynn wrote:
> Gundala Viswanath wrote:
> 
>> Typically  Perl's idiom would be:
>> 
>> __BEGIN__
>> @files = glob("/mydir/*.txt");
>> 
>> foreach my $file (@files) {
>>   # process the file
>> }
>> __END__
> 
> Something like this has been suggested in R-help before:
> 
> files <- dir()
> results <- lapply(files, yourprocessing())
> 
> The dir function has path and pattern arguments to select the set of 
> files you want.
> 
> This works fine when there are no problems, but often I'll use a for 
> loop so problem files can be dealt with differently when necessary.
> 
> Perhaps something like this:
> 
> ProcessList <- dir(pattern="InPerson*")
> 
> for (i in 1:length(ProcessList))

Remember to use seq_along() instead:  ProcessList might be length 0.

Duncan Murdoch

> {
>    filename <- ProcessList[i]
>    . . .
> }
> 
> 
> efg
> 
> Earl F Glynn
> Overland Park, KS
> 
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