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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def _init_a(D):
    '''Initial guess for Dirichlet alpha parameters given data D'''
    E = D.mean(axis=0)
    E2 = (D**2).mean(axis=0)
    return ((E[0] - E2[0])/(E2[0]-E[0]**2)) * E