Argmax with random tie-breaking

    Args:
        x: a 1-dim numpy array
    Returns:
        the argmax index

def rargmax(x, eps=1e-8):
    """Argmax with random tie-breaking

    Args:
        x: a 1-dim numpy array
    Returns:
        the argmax index
    """
    idxs = np.where(abs(x - np.max(x, axis=0)) < eps)[0]
    return np.random.choice(idxs)