# statsmodels.tsa.filters.filtertools.recursive_filter¶

statsmodels.tsa.filters.filtertools.recursive_filter(x, ar_coeff, init=None)[source]

Autoregressive, or recursive, filtering.

Parameters: x (array-like) – Time-series data. Should be 1d or n x 1. ar_coeff (array-like) – AR coefficients in reverse time order. See Notes init (array-like) – Initial values of the time-series prior to the first value of y. The default is zero. y – Filtered array, number of columns determined by x and ar_coeff. If a pandas object is given, a pandas object is returned. array

Notes

Computes the recursive filter

y[n] = ar_coeff[0] * y[n-1] + ...
+ ar_coeff[n_coeff - 1] * y[n - n_coeff] + x[n]


where n_coeff = len(n_coeff).