[R] deleting rows containing a letter

[David Winsemius]

On May 11, 2011, at 7:55 AM, chris20 wrote:

> Hi
> I have dataframe with different plot numbers in and different  
> subplots as
> letters at the end of the plot number i.e. 1a, 1b 2-1a etc.
> I want to delete all rows that end in a specific letter eg...
>
> treat<-c("1a","1b","1c","2a","2b","2c","2-1a","2-1b","2-1c")
> a1<-1:9
> b1<-9:1
> d1<-data.frame(treat,a1,b1)
>
 > d1[-grep("c$", d1$treat), ]
   treat a1 b1
1    1a  1  9
2    1b  2  8
4    2a  4  6
5    2b  5  5
7  2-1a  7  3
8  2-1b  8  2

> How do I remove all rows where treat ends in "c" ?  I have tried the  
> usual
> ways of deleting rows but nothing works.

Not sure what the usual ways are for you but negative indexing is the  
usual way for me.

(Could also use subset, I suppose)

>
> Thanks
> Chris
> e.

David Winsemius, MD
West Hartford, CT