numpy.argwhere

numpy.argwhere(a)

Find the indices of array elements that are non-zero, grouped by element.

Parameters:

a : array_like

Input data.

Returns:

index_array : ndarray

Indices of elements that are non-zero. Indices are grouped by element.

See also

where, nonzero

Notes

np.argwhere(a) is the same as np.transpose(np.nonzero(a)).

The output of argwhere is not suitable for indexing arrays. For this purpose use where(a) instead.

Examples

>>> x = np.arange(6).reshape(2,3)
>>> x
array([[0, 1, 2],
       [3, 4, 5]])
>>> np.argwhere(x>1)
array([[0, 2],
       [1, 0],
       [1, 1],
       [1, 2]])