R help - Oct 2011 - delete columns which partially match expression

Hello everyone,

 

I'd like to search for certain "expressions" (characters) in my
data.frame
and delete the containing columns.

 

So, for example in the below table, I'd like to delete all columns which
contain the expression "Error". That is, R should delete column C and
E from
my data. Any ideas?

 

A             B             C             D             E

12           33           Error1   71           Error2

 

Cheers, S.B.

 


	[[alternative HTML version deleted]]

try this:
> x <- read.table(textConnection("A             B             C      
D             E
+ 12           33           Error1   71           Error2
+ 12           33           Error1   71           Error2
+ 12           33           Error1   71           Error2
+ 12           33           Error1   71           Error2
+ 12           33           Error1   71           Error2")
+     , as.is = TRUE
+     , header = TRUE
+     )
> closeAllConnections()
> colMatch <- which(apply(x, 2, function(a) any(grepl("Error",
a))))
> colMatch
C E
3 5
> # delete columns
> x[, -colMatch]
   A  B  D
1 12 33 71
2 12 33 71
3 12 33 71
4 12 33 71
5 12 33 71
>

On Thu, Oct 13, 2011 at 9:10 AM, Samir Benzerfa <benzerfa at gmx.ch>
wrote:
> Hello everyone,
>
>
>
> I'd like to search for certain "expressions" (characters) in
my data.frame
> and delete the containing columns.
>
>
>
> So, for example in the below table, I'd like to delete all columns
which
> contain the expression "Error". That is, R should delete column C
and E from
> my data. Any ideas?
>
>
>
> A ? ? ? ? ? ? B ? ? ? ? ? ? C ? ? ? ? ? ? D ? ? ? ? ? ? E
>
> 12 ? ? ? ? ? 33 ? ? ? ? ? Error1 ? 71 ? ? ? ? ? Error2
>
>
>
> Cheers, S.B.
>
>
>
>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
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> 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.
>


-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?