How to invert NumPy array
NumPy is a practical Python library for numerical computing that provides an array object and various mathematical functions.
The numpy.flip() function
We can invert a NumPy array using numpy.flip() function. The numpy.flip() function is used to reverse the order of elements in a NumPy array along a specified axis.
Usage
The numpy.flip() method can reverse the order of elements in a NumPy array along different axes. You can flip arrays horizontally, vertically, or along higher-dimensional axes by specifying the desired axis.
Syntax
Below is the syntax for the numpy.flip() function:
numpy.flip(m, axis=None)
mis the input array to be flipped.axis(Optional) is the axis that will be used to reverse the array. The array will be flattened if nothing is supplied before being reversed.
Make sure you have the NumPy library installed (you can install it using pip install numpy).
Code examples
Let's have a look at two different code examples explaining the use of numpy.flip():
Flipping a 1-D Array
import numpy as nparr = np.array([1, 2, 3, 4, 5])flipped_arr = np.flip(arr)print("Original array:", arr)print("Flipped array:", flipped_arr)
Let's understand what happens in the code above:
Line 1: Firstly, we import the NumPy module.
Line 3: Then, we create a NumPy one-dimensional array to perform the inversion.
Line 4: Now, we call
np.flip()with thearrarray as the argument. This function returns a new array with the elements reversed, which we store in the variableflipped_arr.Line 6–7: Finally, we print the original and inverted arrays to observe the changes.
Flipping a 2-D Array
import numpy as nparr = np.array([[1, 2, 3], [4, 5, 6]])flipped_arr = np.flip(arr, axis=0)print("Original array:")print(arr)print("Flipped array:")print(flipped_arr)
Let's understand what happens in the code above:
Line 1: Firstly, we import the NumPy module.
Line 3: Then, we create a NumPy two-dimensional array to perform the inversion.
Line 4: Now, we call
np.flip()with thearrarray as the argument. This function returns a new array with the elements reversed, which we store in the variableflipped_arr.Line 6–9: Finally, we print the original and inverted arrays to observe the changes.
Conclusion
Therefore, inverting a NumPy array can be achieved easily using the numpy.flip() function by reversing the order of elements of the original array along a specified axis. This approach is helpful in various applications, such as rearranging data or performing specific calculations.
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