>>> from scipy.interpolate import interp1d
#interp1d表示1维插值

>>> x = np.linspace(0, 10, num=11, endpoint=True)

>>> y = np.cos(-x**2/9.0)

>>> f = interp1d(x, y)

>>> f2 = interp1d(x, y, kind='cubic')
#kind='cubic' 省去kind参数  默认为线性插值

>>> xnew = np.linspace(0, 10, num=41, endpoint=True)
#xnew表示插值之后，画图，选取的画图点数，再用线将这些点连起来

>>> import matplotlib.pyplot as plt

>>> plt.plot(x, y, 'o', xnew, f(xnew), '-', xnew, f2(xnew), '--')

>>> plt.legend(['data', 'linear', 'cubic'], loc='best')

>>> plt.show()

>>> from scipy.interpolate import interp1d

>>> x = np.linspace(0, 10, num=11, endpoint=True)

>>> y = np.cos(-x**2/9.0)

>>> f1 = interp1d(x, y, kind='nearest')

>>> f2 = interp1d(x, y, kind='previous')

>>> f3 = interp1d(x, y, kind='next')

>>> xnew = np.linspace(0, 10, num=1001, endpoint=True)

>>> import matplotlib.pyplot as plt

>>> plt.plot(x, y, 'o')

>>> plt.plot(xnew, f1(xnew), '-', xnew, f2(xnew), '--', xnew, f3(xnew), ':')

>>> plt.legend(['data', 'nearest', 'previous', 'next'], loc='best')

>>> plt.show()