def SerialCorr(series, lag=1):
 xs = series[lag:]
 ys = series.shift(lag)[lag:]
 corr = Corr(xs, ys)
 return corr

def SerialCorr ( series , lag = 1 ) : xs = series [ lag : ] ys = series . shift ( lag ) [ lag : ] corr = Corr ( xs , ys ) return corr
computes the serial correlation of a series .