scipy.signal.decimate¶
- scipy.signal.decimate(x, q, n=None, ftype='iir', axis=-1, zero_phase=True)[source]¶
Downsample the signal after applying an anti-aliasing filter.
By default, an order 8 Chebyshev type I filter is used. A 30 point FIR filter with Hamming window is used if ftype is ‘fir’.
Parameters: x : ndarray
The signal to be downsampled, as an N-dimensional array.
q : int
The downsampling factor. For downsampling factors higher than 13, it is recommended to call decimate multiple times.
n : int, optional
The order of the filter (1 less than the length for ‘fir’). Defaults to 8 for ‘iir’ and 30 for ‘fir’.
ftype : str {‘iir’, ‘fir’} or dlti instance, optional
If ‘iir’ or ‘fir’, specifies the type of lowpass filter. If an instance of an dlti object, uses that object to filter before downsampling.
axis : int, optional
The axis along which to decimate.
zero_phase : bool, optional
Returns: y : ndarray
The down-sampled signal.
See also
- resample
- Resample up or down using the FFT method.
- resample_poly
- Resample using polyphase filtering and an FIR filter.
Notes
The zero_phase keyword was added in 0.18.0. The possibility to use instances of dlti as ftype was added in 0.18.0.