[R] Does it exist a function for this?

[Jim Lemon]

On 10/05/2011 07:42 PM, lunarossa wrote:
> I have this kind of matrix, with thousands of cases.
>
> A 2 apple
> A 2 peach
> A 3 peach
> B 1 pear
> B 4 peach
> B 4 beef
> B 7 beef
> C 1 peach
> D 2 apple
> D 5 peach
>
> I have to distinguish, from the other rows, the rows with "peach" and this
> is not a problem.
>
> I also have to discriminate the rows with peach like the second one
> (associated with the same two cells "A" and "2" to "apple", see first row)
> from the row like the 3rd or the 8th ones, when the first two cells are
> "unique" ("A" and "3" or "C" and "1").
>
Hi lunarossa,
I may be on the wrong track, but you could just stick the three 
components together:

alphanumfruit[,4]<-paste(alphanumfruit[,1],
  alphanumfruit[,2],alphanumfruit[,3],sep="")

and the fourth column of your object (which I suspect is a data frame) 
will have elements that can be tested for matching or non-matching. More 
complicated conditions can be accommodated by pasting different 
combinations of the columns together.

Jim