def simple_moving_average(x, n=10):
    """
    Calculate simple moving average

    Parameters
    ----------
    x : ndarray
        A numpy array
    n : integer
        The number of sample points used to make average

    Returns
    -------
    ndarray
        A 1 x n numpy array instance
    """
    if x.ndim > 1 and len(x[0]) > 1:
        x = np.average(x, axis=1)
    a = np.ones(n) / float(n)
    return np.convolve(x, a, 'valid')