functions.py 文件源码

def dataWindow(x, f, max_period):
    '''
    Computes a data window of the dataset. That is, a periodogram with
    the all of the RV values and variances set to 1.

    Parameters
    ----------
    x : list
        The times at which the data points were gathered.

    f : float
        The number of samples to take over the interval.

    max_period : float
        The maximum of the interval of periods to check.

    Returns
    -------
    periods : array_like[len(f)]
        Equally spaced array of possible period values.

    powers : array_like[len(f)]
        The calculated Power values over the range of periods,
        these form the normalized Lomb-Scargle Periodogram.

    '''
    from scipy.signal import lombscargle

    # Sort the time data chronologically.
    x = np.sort(np.array(x))
    delta_x = np.inf

    # Iteratively lower the measure delta_x
    for i in range(0, len(x)-2):
        if x[i+1]-x[i] < delta_x and x[i+1]-x[i] != 0:
            delta_x = x[i+1]-x[i]

    periods = np.linspace(delta_x, max_period, num = f)
    ang_freqs = 2 * pi / periods
    powers = lombscargle(x, np.ones(len(x)), ang_freqs)
    powers *= 2 / len(x)

    return periods, powers