chickadee » statistics » mode

returns two values. The first is a list of the modes and the second is the frequency. (A mode of a list of numbers is the most frequently occurring value.)

> (mode '(1 2 3 4))
(1 2 3 4)
1
> (mode '(1 2 2 3 4))
(2)
2
> (mode '(1 2 2 3 3 4))
(2 3)
2