能量函数没有返回值

Question

我在python中创建了一个能量函数，我将其应用于png图像。然而，当我输入参数时，我没有得到返回的能量值。有人知道为什么吗?谢谢你！

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.image as mpimg
img=mpimg.imread('Image.png')
#plt.imshow(img)
#plt.show()
im=np.array(img

def E_generator(beta, eta, h):
    """Generate energy function E and localized version of E.
        E = h * sum{x_i} - beta * sum{x_i x_j} - eta * sum{x_i y_i}
    """
    def E(x, y):
        """Calculate energy for matrices x, y.
        """
        # sum of products of neighboring paris {xi, yi}
        xxm = np.zeros_like(x)
        xxm[:-1, :] = x[1:, :]  # down
        xxm[1:, :] += x[:-1, :]  # up
        xxm[:, :-1] += x[:, 1:]  # right
        xxm[:, 1:] += x[:, :-1]  # left
        xx = np.sum(xxm * x)
        xy = np.sum(x * y)
        xsum = np.sum(x)
        return h * xsum - beta * xx - eta * xy
     return E
y = np.array(img)
x = np.array(y)
E_generator(0,1,1)

然后输出返回:"。E> "

Answer 1

函数E_generator返回一个函数(E);要获得结果，需要调用该函数，因此可以这样做:

print E_generator(0,1,1)(x, y)