Source code for toqito.matrix_ops.perturb_vectors

"""Perturb vectors is used to add a small random number to each element of a vector.

A random value is added sampled from a normal distribution scaled by `eps`.
"""

import numpy as np




def perturb_vectors(vectors: list[np.ndarray], eps: float = 0.1) -> np.ndarray:
    """Perturb the vectors by adding a small random number to each element.

    Example:
    ==========

    ```python exec="1" source="above"
    import numpy as np
    from toqito.matrix_ops import perturb_vectors

    vectors = [np.array([1.0, 2.0]), np.array([3.0, 4.0])]

    print(perturb_vectors(vectors, eps=0.1))
    ```

    Args:
        vectors: List of vectors to perturb.
        eps: Amount by which to perturb vectors.

    Returns:
        Resulting list of perturbed vectors by a factor of epsilon.

    """
    perturbed_vectors: list[np.ndarray] = []
    for i, v in enumerate(vectors):
        if eps == 0:
            perturbed_vectors.append(v)
        else:
            perturbed_vectors.append(v + np.random.randn(v.shape[0]) * eps)

            # Normalize the vectors after perturbing them.
            perturbed_vectors[i] = perturbed_vectors[i] / np.linalg.norm(perturbed_vectors[i])
    return np.array(perturbed_vectors)