[R] using R selecte data record?

I have a database containing all the football tournament, however I want only to filter out all the pairwise events. Briefly: If A matches B & B matches A, we reserve the two tournament, otherwise forsake this tournament. Please help me, thankx. __ R-he

[R] help:Vector vs array

Greetings R-help community, I am relatively new to R, which may be why I am having trouble understanding this problem. I want to know the differences between vector and array. could someone tell me something about this question. Thanks in advance, __ R