`numpy:isfortran`

source: /dev/numpy/build-install/usr/lib/python3.14/site-packages/numpy/_core/numeric.py:553

Signature

def isfortran(a)

Summary

Check if the array is Fortran contiguous but not C contiguous.

Extended Summary

This function is obsolete. If you only want to check if an array is Fortran contiguous use a.flags.f_contiguous instead.

Parameters

a : ndarray: Input array.

Returns

isfortran : bool: Returns True if the array is Fortran contiguous but not C contiguous.

Examples

np.array allows to specify whether the array is written in C-contiguous order (last index varies the fastest), or FORTRAN-contiguous order in memory (first index varies the fastest).

import numpy as np
a = np.array([[1, 2, 3], [4, 5, 6]], order='C')
a
np.isfortran(a)

✓

False

b = np.array([[1, 2, 3], [4, 5, 6]], order='F')
b
np.isfortran(b)

✓

True

The transpose of a C-ordered array is a FORTRAN-ordered array.

a = np.array([[1, 2, 3], [4, 5, 6]], order='C')
a
np.isfortran(a)
b = a.T
b
np.isfortran(b)

✓

True

C-ordered arrays evaluate as False even if they are also FORTRAN-ordered.

np.isfortran(np.array([1, 2], order='F'))

✓

False

Aliases

numpy.isfortran