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# numpy.ma.argsort

`numpy.ma.``argsort`(a, axis=None, kind='quicksort', order=None, fill_value=None)

  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

  `sort`
    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])