filters.py 文件源码

def filter(self, X, Y):
        if self.interpolate:
            X, Y = self.simplefill(X, Y)
        else:
            X, Y = self.sortxy(X, Y)

        order_range = list(range(self.order+1))
        half_window = (self.window_size - 1) // 2
        # precompute coefficients
        b = np.mat([[k**i for i in order_range]
                    for k in range(-half_window, half_window+1)])
        m = np.linalg.pinv(b).A[self.deriv]
        # pad the signal at the extremes with
        # values taken from the signal itself
        firstvals = Y[0] - np.abs(Y[1:half_window+1][::-1] - Y[0])
        lastvals = Y[-1] + np.abs(Y[-half_window-1:-1][::-1] - Y[-1])
        Y1 = np.concatenate((firstvals, Y, lastvals))
        Y2 = np.convolve(m, Y1, mode='valid')

        return X, Y2