R help - Apr 2006 - entries that match a regexp

Hi all,

I am trying to filter the element of a df that start with "TF", like
this:

alfa
c(123221,"TF13124",41243,"TF1234",32414,"TF13124","TF14333",2134123,"TF1234")
beta
c("type_a","type_b","type_a","type_g","type_d","type_a","type_g","type_a","type_g")
mydf = data.frame(alfa,beta)
mydf
tf = mydf[mydf$alfa %in% "TF",]

Shouldn't the %in% operator to the trick here?

Thanks in advance,

    Albert.

Albert Vilella wrote:
> Hi all,
> 
> I am trying to filter the element of a df that start with "TF",
like
> this:
> 
> alfa >
c(123221,"TF13124",41243,"TF1234",32414,"TF13124","TF14333",2134123,"TF1234")
> beta >
c("type_a","type_b","type_a","type_g","type_d","type_a","type_g","type_a","type_g")
> mydf = data.frame(alfa,beta)
> mydf
> tf = mydf[mydf$alfa %in% "TF",]
> 
> Shouldn't the %in% operator to the trick here?
tf <- mydf[grep("^TF", as.character(mydf$alfa)),]
> Thanks in advance,
> 
>     Albert.
> 
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I think that you want to use 'grep' after converting the factors to
characters:
> tf = mydf[grep("TF", as.character(mydf$alfa)),]
> tf
     alfa   beta
2 TF13124 type_b
4  TF1234 type_g
6 TF13124 type_a
7 TF14333 type_g
9  TF1234 type_g
>


On 4/28/06, Albert Vilella <avilella@gmail.com>
wrote:
>
> Hi all,
>
> I am trying to filter the element of a df that start with "TF",
like
> this:
>
> alfa >
>
c(123221,"TF13124",41243,"TF1234",32414,"TF13124","TF14333",2134123,"TF1234")
> beta >
>
c("type_a","type_b","type_a","type_g","type_d","type_a","type_g","type_a","type_g")
> mydf = data.frame(alfa,beta)
> mydf
> tf = mydf[mydf$alfa %in% "TF",]
>
> Shouldn't the %in% operator to the trick here?
>
> Thanks in advance,
>
>    Albert.
>
> ______________________________________________
> R-help@stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html
>


--
Jim Holtman
Cincinnati, OH
+1 513 646 9390 (Cell)
+1 513 247 0281 (Home)

What the problem you are trying to solve?

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