Validates regular sampling of a 1D array ensuring that the difference
    in sampling steps is at most rtol times the smallest sampling step.
    Returns a boolean indicating whether the sampling is regular.

def validate_regular_sampling(values, rtol=10e-6):
    """
    Validates regular sampling of a 1D array ensuring that the difference
    in sampling steps is at most rtol times the smallest sampling step.
    Returns a boolean indicating whether the sampling is regular.
    """
    diffs = np.diff(values)
    return (len(diffs) < 1) or abs(diffs.min()-diffs.max()) < abs(diffs.min()*rtol)