i need to implement a project with visual intimacy between persons,can anyone recommends an algorithm for person's intimacy in phone contact? intimacy attenuate over time(the intimacy attenuates automatically if you havnt click/dial it for a long time). Assume in my address book: Person Intimacy(0-100%) A 40% B 80% C 10% A's intimacy needs raise after i call A ,like this Person Intimacy(0-100%) A 42% B 80% C 10% nothing happens after follow 5 days, A,B,C's intimacy need decline,like this Person Intimacy(0-100%) A 37% B 78% C 8% thanks for everyone's answer