NumPy Array Sort
Sorting arrays in NumPy allows you to organize data in ascending or descending order. Sorting is available for both 1D and multi-dimensional arrays, making it useful for tasks like ranking population densities or temperatures.
Key Topics
Sorting 1D Arrays
The sort()
function sorts a 1D array in ascending order by default.
Example
# Sorting a 1D array
import numpy as np
temperatures_chennai = np.array([32, 35, 30, 33, 31])
temperatures_chennai.sort()
print("Sorted temperatures in Chennai:", temperatures_chennai)
Output
Sorted temperatures in Chennai: [30 31 32 33 35]
Explanation: The sort()
method arranges the array elements in ascending order. For 1D arrays, the method operates on the entire array.
Sorting 2D Arrays
For 2D arrays, you can sort along a specific axis. By default, sorting is row-wise (axis=1).
Example
# Sorting a 2D array
rainfall_data = np.array([[200, 100, 300], [150, 250, 50]])
rainfall_data.sort(axis=1)
print("Row-wise sorted rainfall data:")
print(rainfall_data)
Output
Row-wise sorted rainfall data:
[[100 200 300]
[ 50 150 250]]
[[100 200 300]
[ 50 150 250]]
Explanation: Setting axis=1
sorts each row individually. Similarly, you can set axis=0
to sort columns.
Key Takeaways
- Sorting 1D Arrays: Use
sort()
to arrange array elements in ascending order. - Sorting 2D Arrays: Specify the
axis
to sort rows or columns. - In-Place Sorting: The
sort()
function modifies the original array. - Example Use: Organize temperatures or rainfall data for easier analysis.