numpy.ma.notmasked_edges — NumPy v1.15 Manual (original) (raw)

numpy.ma. notmasked_edges(a, axis=None)[source]

Find the indices of the first and last unmasked values along an axis.

If all values are masked, return None. Otherwise, return a list of two tuples, corresponding to the indices of the first and last unmasked values respectively.

Parameters: a : array_like The input array. axis : int, optional Axis along which to perform the operation. If None (default), applies to a flattened version of the array.
Returns: edges : ndarray or list An array of start and end indexes if there are any masked data in the array. If there are no masked data in the array, edges is a list of the first and last index.

Examples

a = np.arange(9).reshape((3, 3)) m = np.zeros_like(a) m[1:, 1:] = 1

am = np.ma.array(a, mask=m) np.array(am[~am.mask]) array([0, 1, 2, 3, 6])

np.ma.notmasked_edges(ma) array([0, 6])