def cmoment(X, n, condition=None, **kwargs):
 mu = expectation(X, condition, **kwargs)
 return moment(X, n, mu, condition, **kwargs)

def cmoment ( X , n , condition = None , ** kwargs ) : mu = expectation ( X , condition , ** kwargs ) return moment ( X , n , mu , condition , ** kwargs )
return the nth central moment of a random expression about its mean i .