numpy.ma.argsort¶

numpy.ma.argsort(a,axis=<no value>,kind='quicksort',order=None,endwith=True,fill_value=None)[source]¶

Return an ndarray of indices that sort the array along thespecified axis. Masked values are filled beforehand tofill_value.

Parameters:

axis:int, optional Axis along which to sort. If None, the default, the flattened arrayis used. Changed in version 1.13.0:Previously, the default was documented to be -1, but that wasin error. At some future date, the default will change to -1, asoriginally intended.Until then, the axis should be given explicitly whenarr.ndim>1, to avoid a FutureWarning. kind:{‘quicksort’, ‘mergesort’, ‘heapsort’, ‘stable’}, optional Sorting algorithm. order:list, optional Whena is an array with fields defined, this argument specifieswhich fields to compare first, second, etc. Not all fields need bespecified. endwith:{True, False}, optional Whether missing values (if any) should be treated as the largest values(True) or the smallest values (False)When the array contains unmasked values at the same extremes of thedatatype, the ordering of these values and the masked values isundefined. fill_value:{var}, optional Value used internally for the masked values.Iffill_value is not None, it supersedesendwith.

Returns:

index_array:ndarray, int Array of indices that sorta along the specified axis.In other words,a[index_array] yields a sorteda.

See also

MaskedArray.sort

Describes sorting algorithms used.

lexsort

Indirect stable sort with multiple keys.

ndarray.sort

Inplace sort.

Notes

Seesort for notes on the different sorting algorithms.

Examples

>>>a=np.ma.array([3,2,1],mask=[False,False,True])>>>amasked_array(data = [3 2 --],             mask = [False False  True],       fill_value = 999999)>>>a.argsort()array([1, 0, 2])