def dices(x,y):
    import sets
    x = sets.Set(x)
    y = sets.Set(y)
    common = len(x.intersection(y))
    total = float(len(x) + len(y))
    return 2*common/total
Calculates Dice's coefficient ... (2*number of common terms)/(number of terms in x +
dataset/ETHPy150Open radlab/sparrow/src/main/python/third_party/stats.py/dices