Thanks Henrique. I had actually tried using 6 back-slashes but didn't know
to use 'cat' to see the non-escaped representation (see below to see my
original confusion). Your strsplit, of course, works great. Thanks again!
> a
[1] "a \\\\\\ b" "a \\\\\\ b"
> cat(a)
a \\\ b a \\\ b>
------------------------------------------------------------
Mark W. Kimpel MD ** Neuroinformatics ** Dept. of Psychiatry
Indiana University School of Medicine
15032 Hunter Court, Westfield, IN 46074
(317) 490-5129 Work, & Mobile & VoiceMail
"The real problem is not whether machines think but whether men do." -- B.
F. Skinner
******************************************************************
On Thu, Aug 27, 2009 at 9:15 PM, Henrique Dallazuanna <www...@gmail.com>wrote:
> You need a escape before each backslash:
>
> a <- c('a \\\\\\ b', 'a \\\\\\ b')
> cat(a, "\n")
>
> You can write in this form:
>
> strsplit(a, " .*\\.* ")
>
>
>
> On Thu, Aug 27, 2009 at 10:03 PM, Mark Kimpel <mwkim...@gmail.com> wrote:
>
>> I have a vector of gene symbols, some of which have multiple aliases. In
>> the
>> case of an alias, they are separated by ' \\\ '.
>> Here is a real world example, which would represent one element of my
>> vector:
>> Eif4g2 /// Eif4g2-ps1 /// LOC678831
>>
>> What I would like to do is input the vector into a function and output a
>> vector with just the first alias of each element (or, if there are no
>> aliases, just the one symbol).
>>
>> So I wrote a simple little function to do this:
>> get.first.id.func <- function(vec, splitter){
>> vec.lst <- strsplit(vec, splitter)
>> first.func <- function(vec1){vec1[1]}
>> vec.out <- sapply(vec.lst, first.func)
>> vec.out
>> }
>>
>> For a trivial example, this works:
>> > a <- c("a_b", "c_d")
>> > get.first.id.func(a, "_")
>> [1] "a" "c"
>>
>> I am running into problems, however, with the real world split of ' \\\ '
>> I'm not even able to construct a sample vector of my own! Here is what I
>> get:
>> > a <- c('a \\\ b', 'a \\\ b')
>> > a
>> [1] "a \\ b" "a \\ b"
>> > a <- c('a \\\\ b', 'a \\\\ b')
>> > a
>> [1] "a \\\\ b" "a \\\\ b"
>>
>> I KNOW this is related to R's peculiarities with \ escapes, but I don't
>> have
>> the expertise to know how to get around it.
>>
>> I would be very interested to learn:
>> 1. how to construct a vector such that a == c('a \\\ b', 'a \\\ b')
>> 2. how to properly input my split into my function so that I get the split
>> desired.
>>
>> Thanks regex experts!
>> Mark
>>
>> ------------------------------------------------------------
>> Mark W. Kimpel MD ** Neuroinformatics ** Dept. of Psychiatry
>> Indiana University School of Medicine
>>
>> 15032 Hunter Court, Westfield, IN 46074
>>
>> (317) 490-5129 Work, & Mobile & VoiceMail
>>
>> "The real problem is not whether machines think but whether men do." -- B.
>> F. Skinner
>> ******************************************************************
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help@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.
>>
>
>
>
> --
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O
>
[[alternative HTML version deleted]]
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