What is the numpy.asfortranarray() function in Python?

Overview

The asfortranarray() function in Python is used to return an array with ndim >= 1 laid out in a Fortran-style or order in memory.

Note: Fortran order (F-order) is a type of memory layout in which all the elements of a given array are stored in column-major order.

Syntax

numpy.asfortranarray(a, dtype=None, *, like=None)
Syntax for the asfortranarray() function in Python

Parameters

The asfortranarray() function takes the following parameter values:

  • a(required): This is the input array.
  • dtype(optional): This is the data type of the desired output array. It is inferred from the input array.
  • like(optional): This is an array-like reference object which allows the creation of arrays that are not NumPy arrays.

Example

import numpy as np

# creating an input array

a = np.arange(8).reshape(2,4)



# implementing the asfortranarray() function

myarray = np.asfortranarray(a)



# check to see if the input array, a, is in F-order memory layout

print(a.flags['F_CONTIGUOUS'])



# check to see if the new array, myarraya,  is in F-order memory layout

print(myarray.flags['F_CONTIGUOUS'])

Explanation

  • Line 1: We import the numpy module.
  • Line 3: We create an input array, a, using the array() function.
  • Line 6: We call the asfortranarray() function and pass the input array, a, as its argument. The result is assigned to a variable, myarray.
  • Line 9: Using the flag attribute, we check the memory layout of the input array, a, to see if it is laid out in F-order.
  • Line 12: Using the flag attribute, we check the memory layout of the new array, myarray, to see if it is laid out in F-order.

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