按Fortran顺序显示Numpy数组

Fortran顺序/数组是一种特殊情况，数组中的所有元素都是以列为主的顺序存储。有时我们需要按fortran顺序显示数组，为此numpy有一个函数称为numpy.nditer() 。

语法: numpy.nditer(op, flags=None, op_flags=None, op_dtypes=None, order=’K’, casting=’safe’, op_axes=None, itershape=None, buffersize=0)

示例 1:

# importing Numpy package
import numpy as np
  
# creating a Numpy array
num_array = np.arange(12).reshape(3, 4)
  
print("Array:")
print(num_array)
  
# Display array in Fortran order
# using numpy.nditer()
print("\nElements of the array in Fortan array:")
for num_array in np.nditer(num_array, order="F"):
    print(num_array, end=' ')

输出:

Array:
[[ 0  1  2  3]
[ 4  5  6  7]
[ 8  9 10 11]]

Elements of the array in Fortan array:
0 4 8 1 5 9 2 6 10 3 7 11

示例 2:

# importing Numpy package 
import numpy as np
  
# creating a Numpy array
num_array = np.arange(12).reshape(2, 6)
      
print("Array:")
print(num_array)
  
# Display array in Fortran order 
# using numpy.nditer() 
print("\nElements of the array in Fortan array:")
for num_array in np.nditer(num_array, order="F"):
    print(num_array,end=' ')

输出:

Array:
[[ 0  1  2  3  4  5]
[ 6  7  8  9 10 11]]

Elements of the array in Fortan array:
0 6 1 7 2 8 3 9 4 10 5 11

示例 3:

# importing Numpy package 
import numpy as np
  
# creating a Numpy array
num_array = np.arange(42).reshape(6, 7)
      
print("Array:")
print(num_array)
  
# Display array in Fortran order 
# using numpy.nditer() 
print("\nElements of the array in Fortan array:")
for num_array in np.nditer(num_array, order="F"):
    print(num_array,end=' ')

输出:

Array:   
[[ 0 1 2 3 4 5 6]   
[ 7 8 9 10 11 12 13]   
[14 15 16 17 18 19 20]   
[21 22 23 24 25 26 27]   
[28 29 30 31 32 33 34]   
[35 36 37 38 39 40 41]] 

Elements of the array in Fortan array:   
0 7 14 21 28 35 1 8 15 22 29 36 2 9 16 23 30 37 3 10 17 24 31 38 4 11 18 25 32 39 5 12 19 26 33 40 6 13 20 27 34 41