statsmodels.sandbox.tsa.fftarma.ArmaFft.invertroots

method

ArmaFft.invertroots(retnew=False)

Make MA polynomial invertible by inverting roots inside unit circle

Parameters

retnewboolean

If False (default), then return the lag-polynomial as array. If True, then return a new instance with invertible MA-polynomial

Returns

manewarray

new invertible MA lag-polynomial, returned if retnew is false.

wasinvertibleboolean

True if the MA lag-polynomial was already invertible, returned if retnew is false.

armaprocessnew instance of class

If retnew is true, then return a new instance with invertible MA-polynomial