[英]how to extract a zero-dimensional slice from a 1-dimensional array in numpy
Is there a way to slice a zero-dimensional sub-array from a 1-dimensional array? 有没有办法从一维数组切割零维子阵列?
For example, if I have a N-dimensional ndarray
arr
, arr[0]
returns a (N-1)-dimensional ndarray
. 例如,如果我有一个N维的ndarray
arr
, arr[0]
返回一个(N-1)维的ndarray
。
However, if I have a 1-dimensional ndarray
x
, x[0]
doesn't return a 0-dimensional ndarray, but rather a numpy.int64
, (if x
contains int64
s). 但是,如果我有一维ndarray
x
, x[0]
不返回0维ndarray,而是返回numpy.int64
,(如果x
包含int64
s)。
Minimal example: 最小的例子:
def increment(zero_d_array):
zero_d_array[...] = zero_d_array + 1
counter = numpy.array(0) # a zero-dimensional array containing scalar 0
increment(counter) # success; counter is now 1
counters = numpy.zeros(3, dtype=int) # [0, 0, 0]
increment(counter[1]) # fails; counter[1] is a numpy.int64, not a 0-D array
I realize the above would work with increment(counter[1:2])
, but only because increment()
happens to work with both 0-D and 1-D inputs. 我意识到上面的方法可以用increment(counter[1:2])
,但只是因为increment()
恰好适用于0-D和1-D输入。 Not all functions will be so flexible. 并非所有功能都会如此灵活。
使用省略号:
increment(counter[1, ...])
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.