np.diff（np.signbit（））不再找到过零点，更好的方法？

Question

我正在寻找这个answer，但由于布尔减法已经折旧，它不再有效。还有更好的方法吗？

A   = np.array([[-2, -1,  1], 
                [-1,  0,  1], 
                [-1,  1,  2]], dtype=float)

zcs = np.diff(np.signbit(A), axis=1)     # find zero crossings in each row - now fails

产生

Traceback (most recent call last):
  File "/Users/david/Documents/wow.py", line 4, in <module>
    zcs = np.diff(np.signbit(A), axis=1)     # now fails
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy/lib/function_base.py", line 1926, in diff
    return a[slice1]-a[slice2]

TypeError: numpy boolean subtract, the `-` operator, is deprecated, use the bitwise_xor, the `^` operator, or the logical_xor function instead.

Answer 1

这显然已在1.14.0中修复，但作为快速修复显式类型转换：

zcs = np.diff(np.signbit(A).astype(int), axis=1) 

应该有效。