def het_arch(resid, maxlag=None, autolag=None, store=False, regresults=False, ddof=0):
 return acorr_lm((resid ** 2), maxlag=maxlag, autolag=autolag, store=store, regresults=regresults)

def het_arch ( resid , maxlag = None , autolag = None , store = False , regresults = False , ddof = 0 ) : return acorr_lm ( ( resid ** 2 ) , maxlag = maxlag , autolag = autolag , store = store , regresults = regresults )
engles test for autoregressive conditional heteroscedasticity parameters resid : ndarray .