def evaluations(ty, pv):
    """
	evaluations(ty, pv) -> ACC

	Calculate accuracy using the true values (ty) and predicted values (pv).
	"""
    if len(ty) != len(pv):
        raise ValueError("len(ty) must equal to len(pv)")
    total_correct = total_error = 0
    for v, y in zip(pv, ty):
        if y == v:
            total_correct += 1
    l = len(ty)
    ACC = 100.0 * total_correct / l
    return ACC