NumPy 中的 rollaxis函数

此功能使指定的轴向后滚动，直到它位于指定的位置，该函数具有三个参数。

numpy.rollaxis(arr, axis, start)

# It creates 3 dimensional ndarray 
import numpy as np 
a = np.arange(8).reshape(2,2,2) 

print 'The original array:' 
print a 
print '\n'
# to roll axis-2 to axis-0 (along width to along depth) 

print 'After applying rollaxis function:' 
print np.rollaxis(a,2)  
# to roll axis 0 to 1 (along width to height) 
print '\n' 

print 'After applying rollaxis function:' 
print np.rollaxis(a,2,1)

其输出如下-

The original array:
[[[0 1]
 [2 3]]
 [[4 5]
 [6 7]]]

After applying rollaxis function:
[[[0 2]
 [4 6]]
 [[1 3]
 [5 7]]]

After applying rollaxis function:
[[[0 2]
 [1 3]]
 [[4 6]
 [5 7]]]