numpy.flatnonzero¶
- numpy.flatnonzero(a)[source]¶
Return indices that are non-zero in the flattened version of a.
This is equivalent to a.ravel().nonzero()[0].
Parameters: a : ndarray
Input array.
Returns: res : ndarray
Output array, containing the indices of the elements of a.ravel() that are non-zero.
See also
Examples
>>> x = np.arange(-2, 3) >>> x array([-2, -1, 0, 1, 2]) >>> np.flatnonzero(x) array([0, 1, 3, 4])
Use the indices of the non-zero elements as an index array to extract these elements:
>>> x.ravel()[np.flatnonzero(x)] array([-2, -1, 1, 2])