.floor()

In the NumPy library, the .floor() method rounds down a number or an array of numbers to the nearest integer that is less than or equal to the given value. It returns an array, with the elements separated by commas. This function is especially useful in mathematical, statistical, and engineering applications where downward rounding is required.

Note: To view the output with commas, use the .repr() function in Python.

Syntax

numpy.floor(input, out=None)

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Parameters:

• input: The input value or array of values for which the floor operation is performed. This can be a single number, or a NumPy array (or any array-like object).
• out (Optional): An output array where the rounded results will be stored. A new array is created to store the rounded-down values if not provided.

Return value:

• If input is a number, the .floor() method returns the largest integer less than or equal to the number (rounded down).
• If input is an array, the method returns a new array containing the rounded-down values for each element in the input array.

Example 1: Using .floor() on Arrays

This example uses the .floor() method to round down an array of numbers:

import numpy as np

# Create an array of numbers
array_unrounded = [4.734, 3.141, 9.567]

# Round down the numbers in the array
array_rounded = np.floor(array_unrounded)

# Print the result
print(array_rounded)

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Here is the output of this code:

[4. 3. 9.]

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Example 2: Using .floor() on Numbers

This example uses the .floor() method to round down a number:

import numpy as np

# Store the number in a variable
num = 5.8

# Round down the number
rounded_num = np.floor(num)

# Print the result
print(rounded_num)

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Here is the output for this code:

5.0

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Codebyte Example: Using .floor() on 2D Arrays

This codebyte example uses the .floor() method to round down the numbers in a 2D array:

import numpy as np

# Create a 2D array of numbers
arr_2d = np.array([[3.9, -1.2], [0.5, -0.9]])

# Round down the numbers in the array
floored_2d = np.floor(arr_2d)

# Print the result
print(floored_2d)

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Frequently Asked Questions

1. What is the difference between NumPy .ceil() and .floor()?

• np.floor() rounds values down to the nearest smallest integer.
• np.ceil() rounds values up to the nearest biggest integer.

2. Does np.floor() modify the original array?

No, np.floor() returns a new array and does not change the original one unless you explicitly use the out parameter to overwrite it.

3. What’s the difference between np.floor() and np.trunc()?

• np.floor() rounds down to the nearest smallest integer (toward negative infinity).
• np.trunc() truncates the decimal part and rounds toward zero.