[R] looking for matches

Stavros Macrakis macrakis at alum.mit.edu
Mon Nov 17 21:31:07 CET 2008

I'm not sure I understand what you're looking for in the result.  What
exactly do you mean by a "match"?  What do you want in the third table
besides the class names?

Do you just want a list (not a data frame) of those class names which
table A and table B have in common?  Then how about

If you want to do something like a SQL join of tables A and B, where
rows are paired up based on common values of the class name, then take
a look at the "merge" function.


On Mon, Nov 17, 2008 at 3:04 PM, Alina Sheyman <alinashe at gmail.com> wrote:
> My question is probably pretty basic, but since I'm really new to R, here it
> goes ....
>  I have two separate data frames that include class names and various other
> information on classes. I'm trying to create a match based on class names
> and if a match exists to create a third data frame with the class name.
> I was hoping to accomplish this with sapply, but I can't figure out if I can
> embed an "if statement" with sapply. Does anyone know if that's a legit way
> to accomplish what I am trying to do or is there some better way?
> thank you,
> Alina Sheyman
>        [[alternative HTML version deleted]]
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