This pull request addresses a compatibility issue with the scipy library's import statements. Previously, the code attempted to import randn directly from scipy, which is incorrect as scipy does not provide a direct import for random functionalities anymore.

Changes Made:

Removed randn from the from scipy import integrate, randn import line.
Added from numpy import random to use NumPy for random number generation functionalities.
These changes ensure that the code utilizes the correct library for random number generation and maintains compatibility with the latest versions of scipy and numpy.

Benefits:

1. Ensures the codebase is up-to-date with current library versions.
2. Prevents runtime errors due to incorrect imports.

Please review the changes and merge them if they meet the project standards. Thank you for considering this update.