scipy.signal.
czt_points#
- scipy.signal.czt_points(m, w=None, a=1 + 0j)[source]#
- Return the points at which the chirp z-transform is computed. - Parameters:
- mint
- The number of points desired. 
- wcomplex, optional
- The ratio between points in each step. Defaults to equally spaced points around the entire unit circle. 
- acomplex, optional
- The starting point in the complex plane. Default is 1+0j. 
 
- Returns:
- outndarray
- The points in the Z plane at which - CZTsamples the z-transform, when called with arguments m, w, and a, as complex numbers.
 
 - See also - Examples - Plot the points of a 16-point FFT: - >>> import numpy as np >>> from scipy.signal import czt_points >>> points = czt_points(16) >>> import matplotlib.pyplot as plt >>> plt.plot(points.real, points.imag, 'o') >>> plt.gca().add_patch(plt.Circle((0,0), radius=1, fill=False, alpha=.3)) >>> plt.axis('equal') >>> plt.show()   - and a 91-point logarithmic spiral that crosses the unit circle: - >>> m, w, a = 91, 0.995*np.exp(-1j*np.pi*.05), 0.8*np.exp(1j*np.pi/6) >>> points = czt_points(m, w, a) >>> plt.plot(points.real, points.imag, 'o') >>> plt.gca().add_patch(plt.Circle((0,0), radius=1, fill=False, alpha=.3)) >>> plt.axis('equal') >>> plt.show() 