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How to get the n-largest values of an array using NumPy?
• Last Updated : 29 Aug, 2020

Let’s see the program for how to get the n-largest values of an array using NumPy library. For getting n-largest values from a NumPy array we have to first sort the NumPy array using numpy.argsort() function of NumPy then applying slicing concept with negative indexing.

Syntax: numpy.argsort(arr, axis=-1, kind=’quicksort’, order=None)

Return: [index_array, ndarray] Array of indices that sort arr along the specified axis.If arr is one-dimensional then arr[index_array] returns a sorted arr.

Let’s see an example:

Example 1: Getting the 1st largest value from a NumPy array.

## Python3

 `# import library``import` `numpy as np`` ` `# create numpy 1d-array``arr ``=` `np.array([``2``, ``0``,  ``1``, ``5``,``                ``4``, ``1``, ``9``])`` ` `print``(``"Given array:"``, arr)`` ` `# sort an array in``# ascending order`` ` `# np.argsort() return``# array of indices for``# sorted array``sorted_index_array ``=` `np.argsort(arr)`` ` `# sorted array``sorted_array ``=` `arr[sorted_index_array]`` ` `print``(``"Sorted array:"``, sorted_array)`` ` `# we want 1 largest value``n ``=` `1`` ` `# we are using negative``# indexing concept`` ` `# take n largest value``rslt ``=` `sorted_array[``-``n : ]`` ` `# show the output``print``(``"{} largest value:"``.``format``(n),``      ``rslt[``0``])`

Output:

```Given array: [2 0 1 5 4 1 9]
Sorted array: [0 1 1 2 4 5 9]
1 largest value: 9
```

Example 2: Getting the 3-largest values from a NumPy array.

## Python3

 `# import library``import` `numpy as np`` ` `# create numpy 1d-array``arr ``=` `np.array([``2``, ``0``,  ``1``, ``5``,``                ``4``, ``1``, ``9``])`` ` `print``(``"Given array:"``, arr)`` ` `# sort an array in``# ascending order`` ` `# np.argsort() return``# array of indices for``# sorted array``sorted_index_array ``=` `np.argsort(arr)`` ` `# sorted array``sorted_array ``=` `arr[sorted_index_array]`` ` `print``(``"Sorted array:"``, sorted_array)`` ` `# we want 3 largest value``n ``=` `3`` ` `# we are using negative``# indexing concept`` ` `# find n largest value``rslt ``=` `sorted_array[``-``n : ]`` ` `# show the output``print``(``"{} largest value:"``.``format``(n),``      ``rslt)`

Output:

```Given array: [2 0 1 5 4 1 9]
Sorted array: [0 1 1 2 4 5 9]
3 largest value: [4 5 9]
```

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