[R] tapply and functions with more than one objects

[Dominic Roye]

Hello,

How i can use a costum function in tapply which has more than one variable?

I mean sum(x) only needs one object but what when i have a function
function(x,y) with more, how i indicate where are the other variables
to use?7


I hope someone can help me. Thank you!!

Best regards,

Dominic