chatExcel

import numpy as np from scipy.signal import convolve def _ricker(points, a): A = 2 / (np.sqrt(3 * a) * (np.pi**0.25)) wsq = a**2 vec = np.arange(0, points) - (points - 1.0) / 2 xsq = vec**2 mod = (1 - xsq / wsq) gauss = np.exp(-xsq / (2 * wsq)) total = A * mod * gauss return total def _cwt(data, wavelet, widths, dtype=None, **kwargs): # Determine output type if dtype is None: if np.asarray(wavelet(1, widths[0], **kwargs)).dtype.char in 'FDG': dtype = np.complex128 else: dtype = np.float64 output = np.empty((len(widths), len(data)), dtype=dtype) for ind, width in enumerate(widths): N = np.min([10 * width, len(data)]) wavelet_data = np.conj(wavelet(N, width, **kwargs)[::-1]) output[ind] = convolve(data, wavelet_data, mode='same') return output