NumPy - Rounding Decimal ufunc

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Rounding Decimal Universal Function (ufunc)

A rounding decimal universal function (ufunc) in NumPy is a function designed to round the elements of an array to a specified number of decimal places. These ufuncs perform the rounding operation element-wise, ensuring that each value in the array is rounded according to the specified precision.

NumPy provides several rounding ufuncs, such as numpy.around(), numpy.floor(), numpy.ceil(), and numpy.trunc(), each with a slightly different way of handling the rounding.

The numpy.around() Function

The numpy.around() function is used to round elements of an array to the specified number of decimals. It is versatile and can handle both integer and floating-point numbers.

Example

In the following example, we use the numpy.around() function to round elements of an array to 1 decimal place −

import numpy as np

# Define an array
a = np.array([1.123, 2.456, 3.789])

# Round elements to 1 decimal place
result = np.around(a, decimals=1)

print(result)

Following is the output obtained −

[1.1 2.5 3.8]

The numpy.round_() Function

The numpy.round_() function is an alias for numpy.around() function. It behaves the same way and rounds elements of an array to the specified number of decimals.

Example

In the following example, we use the numpy.round_() function to round elements of an array to 2 decimal places −

import numpy as np

# Define an array
a = np.array([1.12345, 2.45678, 3.78901])

# Round elements to 2 decimal places
result = np.round_(a, decimals=2)

print(result)

This will produce the following result −

[1.12 2.46 3.79]

The numpy.floor() Function

The numpy.floor() function is used to round elements of an array down to the nearest integer. It returns the largest integer less than or equal to each element in the array.

Example

In the following example, we use the numpy.floor() function to round elements of an array down to the nearest integer −

import numpy as np

# Define an array
a = np.array([1.7, 2.3, 3.9])

# Apply floor function
result = np.floor(a)

print(result)

Following is the output of the above code −

[1. 2. 3.]

The numpy.ceil() Function

The numpy.ceil() function is used to round elements of an array up to the nearest integer. It returns the smallest integer greater than or equal to each element in the array.

Example

In the following example, we use the numpy.ceil() function to round elements of an array up to the nearest integer −

import numpy as np

# Define an array
a = np.array([1.2, 2.5, 3.1])

# Apply ceil function
result = np.ceil(a)

print(result)

This will produce the following result −

[2. 3. 4.]

The numpy.trunc() Function

The numpy.trunc() function is used to truncate elements of an array to their integer parts by removing the fractional parts.

Example

In the following example, we use the numpy.trunc() function to truncate elements of an array −

import numpy as np

# Define an array
a = np.array([1.9, 2.6, 3.4])

# Apply trunc function
result = np.trunc(a)

print(result)

Following is the output obtained −

[1. 2. 3.]