Question

我有以下代码：

import numpy as np
def J(x, y):
    return np.matrix([[8-(4 * y), -4 * y], [y, -5 + x]])

x_0 = np.matrix([[1], [1]])
test = J(x_0[0], x_0[1])

当我去运行它时，我收到以下错误：

Traceback (most recent call last):
  File "broyden.py", line 15, in <module>
    test = J(x_0[0][0], x_0[1][0])
  File "broyden.py", line 12, in J
    return np.matrix([[8-(4 * y), -4 * y], [y, -5 + x]])
  File "/home/collin/anaconda/lib/python2.7/site-packages/numpy/matrixlib/defmatrix.py", line 261, in __new__
    raise ValueError("matrix must be 2-dimensional")
ValueError: matrix must be 2-dimensional

我不明白为什么我会收到此错误。一切似乎都是2-d。

Answer 1

x_0[0]的类型仍然是numpy.matrixlib.defmatrix.matrix，而不是标量值。您需要获得一个比例值作为矩阵元素。试试这段代码

test = J(x_0.item(0), x_0.item(1))

Numpy矩阵必须是二维误差

1 个答案: