ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

This error message is raised when trying to evaluate an array as a boolean expression, but the array has more than one element, making it unclear which boolean value should be returned.

To resolve this error, you need to specify whether you want to check if all elements in the array are true (use `a.all()`) or if any element is true (use `a.any()`).

For example:

import numpy as np

a = np.array([1, 2, 3])
if a.all():
    print("All elements are non-zero")
elif a.any():
    print("At least one element is non-zero")
else:
    print("All elements are zero")

In this example, `a.all()` will return True if all elements in `a` are non-zero, while `a.any()` will return True if at least one element is non-zero.