scipy.special.sinc

scipy.special.sinc(x)

返回sinc函数。

sinc函数是 \(\sin(\pi x)/(\pi x)\)

参数
xndarray

要计算的值的数组(可能是多维 sinc(x)

退货
outndarray

sinc(x) ,它具有与输入相同的形状。

注意事项

sinc(0) 是极限值1。

SINC是“正弦基数”或“基数窦”的缩写。

SINC函数用于各种信号处理应用,包括反走样、构建兰佐斯重采样过滤和插值。

对于离散时间信号的带限内插,理想内插核与SINC函数成正比。

参考文献

1

作者:EricW.“sinc函数。”摘自MathWorld--一个Wolfram Web资源。http://mathworld.wolfram.com/SincFunction.html

2

维基百科,“SINC功能”,https://en.wikipedia.org/wiki/Sinc_function

示例

>>> import matplotlib.pyplot as plt
>>> x = np.linspace(-4, 4, 41)
>>> np.sinc(x)
 array([-3.89804309e-17,  -4.92362781e-02,  -8.40918587e-02, # may vary
        -8.90384387e-02,  -5.84680802e-02,   3.89804309e-17,
        6.68206631e-02,   1.16434881e-01,   1.26137788e-01,
        8.50444803e-02,  -3.89804309e-17,  -1.03943254e-01,
        -1.89206682e-01,  -2.16236208e-01,  -1.55914881e-01,
        3.89804309e-17,   2.33872321e-01,   5.04551152e-01,
        7.56826729e-01,   9.35489284e-01,   1.00000000e+00,
        9.35489284e-01,   7.56826729e-01,   5.04551152e-01,
        2.33872321e-01,   3.89804309e-17,  -1.55914881e-01,
       -2.16236208e-01,  -1.89206682e-01,  -1.03943254e-01,
       -3.89804309e-17,   8.50444803e-02,   1.26137788e-01,
        1.16434881e-01,   6.68206631e-02,   3.89804309e-17,
        -5.84680802e-02,  -8.90384387e-02,  -8.40918587e-02,
        -4.92362781e-02,  -3.89804309e-17])
>>> plt.plot(x, np.sinc(x))
[<matplotlib.lines.Line2D object at 0x...>]
>>> plt.title("Sinc Function")
Text(0.5, 1.0, 'Sinc Function')
>>> plt.ylabel("Amplitude")
Text(0, 0.5, 'Amplitude')
>>> plt.xlabel("X")
Text(0.5, 0, 'X')
>>> plt.show()
../../_images/scipy-special-sinc-1.png