[英]Python Numpy; difference between colon and ellipsis indexing
I have been experimenting with Numpy array indexing using both colon and ellipsis.我一直在尝试使用冒号和省略号进行 Numpy 数组索引。 However, I cannot understand the results that I am getting.
但是,我无法理解我得到的结果。
Below is the example code:下面是示例代码:
>>> a = np.array([[1,2],[3,4]])
>>> a
array([[1, 2],
[3, 4]])
>>> a[:,np.newaxis] # <-- the shape of the rows are unchanged
array([[[1, 2]],
[[3, 4]]])
>>> a[...,np.newaxis] # <-- the shape of the rows changed from horizontal to vertical
array([[[1],
[2]],
[[3],
[4]]])
The original is (2,2)原来是(2,2)
With:, it becomes (2,1,2).有了:,它就变成了 (2,1,2)。 The new axis added after the first dimension.
在第一个维度之后添加的新轴。
With... the shape is (2,2,1), the new shape is added last.使用...形状为 (2,2,1),最后添加新形状。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.