[R] Identify Objects that end with .f (and all caps)

[David Winsemius]

On May 14, 2011, at 3:57 PM, David Winsemius wrote:

>
> On May 14, 2011, at 3:38 PM, Sparks, John James wrote:
>
>> Dear R Helpers,
>>
>> I am trying to find a way to identify all the objects in my  
>> environment
>> that are all caps and then end with .f.  I can do the all caps part  
>> pretty
>> easily, but I have tried a number of variations on the \ and can't  
>> get a
>> recognition of that operator.  As a simple example
>>
>> A.f<-"foo1"
>> AA.f<-"foo2"
>> aa.f<-"foo3"
>> A.a<-"foo4"
>> ls()
>> [1] "A.a"  "A.f"  "aa.f" "AA.f"
>> temp1<-ls(pattern="[A-Z]")
>> temp1
>> [1] "A.a"  "A.f"  "AA.f"
>>> temp2<-ls(pattern=\f)
>> Error: unexpected input in "temp2<-ls(pattern=\"
>
> You need to double the '\':
>
> temp1<-ls(pattern="[A-Z]\\.f")
>
> > temp1
> [1] "A.f"      "AA.f"     "NYSE.A.f"

And if you want to avoid matches such as aaaA.f you need to make  
acouple of other mods:

 > temp1<-ls(pattern="^[A-Z]+\\.f")
 > temp1
[1] "A.f"  "AA.f"


>>
>> The end goal is to isolate A.f and AA.f and not the others.
>> In terms of just getting the 'ending with .f' portion, I have tried a
>> number of variations in the pattern=\f, but can't get R to  
>> recognize what
>> I want.
>>
>> Your guidance would be much appreciated.
>> --John J. Sparks, Ph.D.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> David Winsemius, MD
> West Hartford, CT
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT