[R] "not all duplicated" question

[Vesco Miloushev]

Hi,

I want to select elements which have duplicates by are not all duplicated.

Here is what I mean. Suppose I have a two column matrix with columns
"Country" and "Pet"


Country, Pet
------------------
France, Dog
France, Cat
France, Dog
Canada, Cat
Canada, Cat
Japan, Dog
Japan, Cat
Italy, Cat

I want to extract all the entries that are duplicated in column
"Country" but not ALL duplicated in column "Pet".

In this case I want

Country, Pet
------------------
France, Dog
France, Cat
France, Dog
Japan, Dog
Japan, Cat

Notice that I keep France, because not all are duplicated. If there
was no entry "France, Cat" then it all of the entries with "France"
would be eliminated.

Thanks for your help.