try: from ulab import numpy as np from ulab import scipy as spy except: import numpy as np import scipy as spy x = np.array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]) sos = [[1, 2, 3, 1, 5, 6], [1, 2, 3, 1, 5, 6], [1, 2, 3, 1, 5, 6]] zi = np.array([[1, 2], [3, 4], [5, 6]],dtype=np.float) y, zo = spy.signal.sosfilt(sos, x, zi=zi) print('y: ', y) print('zo: ', zo)