numpy.ma.argsort — NumPy v1.11 Manual (original) (raw)
numpy.ma.argsort(a, axis=None, kind='quicksort', order=None, fill_value=None)[source]¶
Return an ndarray of indices that sort the array along the specified axis. Masked values are filled beforehand to_fill_value_.
| Parameters: | axis : int, optional Axis along which to sort. The default is -1 (last axis). If None, the flattened array is used. fill_value : var, optional Value used to fill the array before sorting. The default is the fill_value attribute of the input array. kind : {‘quicksort’, ‘mergesort’, ‘heapsort’}, optional Sorting algorithm. order : list, optional When a is an array with fields defined, this argument specifies which fields to compare first, second, etc. Not all fields need be specified. |
|---|---|
| Returns: | index_array : ndarray, int Array of indices that sort a along the specified axis. In other words, a[index_array] yields a sorted a. |
See also
Describes sorting algorithms used.
lexsort
Indirect stable sort with multiple keys.
ndarray.sort
Inplace sort.
Notes
See sort for notes on the different sorting algorithms.
Examples
a = np.ma.array([3,2,1], mask=[False, False, True]) a masked_array(data = [3 2 --], mask = [False False True], fill_value = 999999) a.argsort() array([1, 0, 2])