def mean_photon_v(pk1,pk2,pk3,mu1,mu2,mu3):
    """
    Calculate the mean photon number for a signal sent by Alice.
    This function uses individual values.

    Parameters
    ----------
    pk1 : float
        Probability that Alice prepares a signal with intensity 1.
    pk2 : float
        Probability that Alice prepares a signal with intensity 2.
    pk3 : float
        Probability that Alice prepares a signal with intensity 3.
    mu1 : float
        Intensity 1.
    mu2 : float
        Intensity 2.
    mu3 : float
        Intensity 3.

    Returns
    -------
    float
        Mean signal photon number.

    """
    return pk1*mu1 + pk2*mu2 + pk3*mu3