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bundles / numpy 2.5.0.dev0+git20251130.2de293a / numpy / isfortran

function

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This function is obsolete.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)
b = np.array([[1, 2, 3], [4, 5, 6]], order='F')
b
np.isfortran(b)
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)
C-ordered arrays evaluate as False even if they are also FORTRAN-ordered.
np.isfortran(np.array([1, 2], order='F'))

Aliases

  • numpy.isfortran