numpy.isfortran — NumPy v1.13 Manual (original) (raw)
Returns True if the array is Fortran contiguous but not C contiguous.
This function is obsolete and, because of changes due to relaxed stride checking, its return value for the same array may differ for versions of NumPy >= 1.10.0 and previous versions. If you only want to check if an array is Fortran contiguous use a.flags.f_contiguous instead.
| Parameters: | a : ndarray Input array. |
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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).
a = np.array([[1, 2, 3], [4, 5, 6]], order='C') a array([[1, 2, 3], [4, 5, 6]]) np.isfortran(a) False
b = np.array([[1, 2, 3], [4, 5, 6]], order='FORTRAN') b array([[1, 2, 3], [4, 5, 6]]) 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 array([[1, 2, 3], [4, 5, 6]]) np.isfortran(a) False b = a.T b array([[1, 4], [2, 5], [3, 6]]) np.isfortran(b) True
C-ordered arrays evaluate as False even if they are also FORTRAN-ordered.
np.isfortran(np.array([1, 2], order='FORTRAN')) False