statsmodels.tsa.varma_process.VarmaPoly.stacksquare# VarmaPoly.stacksquare(a=None, name='ar', orientation='vertical')[source]# Stack lagpolynomial vertically in 2d square array with eye Parameters: andarray, optionalLag polynomial array to stack. If None, uses self.ar or self.ma, selected by name. name{“ar”, “ma”}, optionalWhich instance lag polynomial to use when a is None. orientationstr, optionalCurrently not used. Returns: ndarrayThe lag polynomial stacked vertically into a 2d square array, with an identity block appended.