cupyx.scipy.signal.sosfilt(sos, x, axis=-1, zi=None)[source]#

Filter data along one dimension using cascaded second-order sections.

Filter a data sequence, x, using a digital IIR filter defined by sos.

  • sos (array_like) – Array of second-order filter coefficients, must have shape (n_sections, 6). Each row corresponds to a second-order section, with the first three columns providing the numerator coefficients and the last three providing the denominator coefficients.

  • x (array_like) – An N-dimensional input array.

  • axis (int, optional) – The axis of the input data array along which to apply the linear filter. The filter is applied to each subarray along this axis. Default is -1.

  • zi (array_like, optional) – Initial conditions for the cascaded filter delays. It is a (at least 2D) vector of shape (n_sections, ..., 4, ...), where ..., 4, ... denotes the shape of x, but with x.shape[axis] replaced by 4. If zi is None or is not given then initial rest (i.e. all zeros) is assumed. Note that these initial conditions are not the same as the initial conditions given by lfiltic or lfilter_zi.


  • y (ndarray) – The output of the digital filter.

  • zf (ndarray, optional) – If zi is None, this is not returned, otherwise, zf holds the final filter delay values.