def METHOD_NAME(x):
    """NumPy implementation of SELU activation.
    The computation is performed with 64-bit floats.
    """
    if x.dtype is not np.float64:
        x = x.astype(np.float64)
    alpha = 1.6732632423543772848170429916717
    scale = 1.0507009873554804934193349852946
    return scale * np.where(x < 0, alpha * np.expm1(x), x)