def get_data_Hofken1982():
    vd = array([1.80, 1.10, 1.00, 0.90, 0.70, 1.00, 1.00, 1.30])
    dp = array([0.26, 0.63, 0.70, 0.78, 1.10, 1.50, 2.20, 2.40])

    vd_err = zeros(8)
    dp_err = zeros(8)
 
    return vd, vd_err, dp, dp_err

def get_data_Hicks1989():
    vd = array([0.25, 0.40])
    dp = array([0.6, 0.075])

    vd_err = array([ [0.24, 0.35], [0.25, 0.35] ])
    dp_err = array([ [0.1, 0.025], [0.1, 0.025] ])

    return vd, vd_err, dp, dp_err

def get_data_Pryor2006():
    vd = array([0.47,  0.31,  0.30,  0.26,  0.15])
    dp = array([0.025, 0.035, 0.045, 0.055, 0.065])

    vd_err = array([ [0.25, 0.20, 0.18, 0.16, 0.03] , [0.29, 0.24, 0.25, 0.27, 0.38] ])
    dp_err = array([0.005, 0.005, 0.005, 0.005, 0.005])
    
    return vd, vd_err, dp, dp_err

def get_data_Pryor2009():
    vd = array([0.360, 0.400, 0.320, 0.300, 0.200, 0.140, 0.180, 0.176, 0.160, 0.140, 0.120, 0.120, 0.108, 0.096, 0.090, 0.084])
    dp = array([0.011, 0.012, 0.014, 0.0165, 0.019, 0.022, 0.026, 0.029, 0.034, 0.039, 0.045, 0.052, 0.060, 0.070, 0.081, 0.093])

    vd_err = zeros(16)
    dp_err = zeros(16)
 
    return vd, vd_err, dp, dp_err

def get_data_Matsuda2010():
    vd = array([0.9])
    dp = array([0.55])

    vd_err = array([0.5])
    dp_err = array([0.45])

    return vd, vd_err, dp, dp_err

def get_data_Gordon2011():
    vd = array([0.40, 0.58, 0.39, 0.26, 0.16, 0.12, 0.11, 0.105, 0.10, 0.095, 0.09, 0.09, 0.08, 0.58, 0.46])
    dp = array([0.017, 0.024, 0.029, 0.035, 0.043, 0.052, 0.062, 0.076, 0.091, 0.11, 0.133, 0.16, 0.194, 0.282, 0.34])

    vd_err = zeros(15)
    dp_err = zeros(15)

    return vd, vd_err, dp, dp_err

def get_data_Sun2014():
    vd = array([0.9])
    dp = array([0.55])

    vd_err = array([0.8])
    dp_err = array([0.45])

    return vd, vd_err, dp, dp_err

def get_data_Matsuda2015():
    vd = array([0.5])
    dp = array([0.55])

    vd_err = array([ [0.22], [0.17] ])
    dp_err = array([0.45])

    return vd, vd_err, dp, dp_err

def get_data_Ahlm2010():
    vd = array([0.35])
    dp = array([0.04])

    vd_err = array([ [0.10], [0.10] ])
    dp_err = array([0.01])

    return vd, vd_err, dp, dp_err

def get_data_Petroff2018():
    vd = array([0.047,  0.086,  0.145,  0.217,  0.269, 0.47, 0.614, 0.937])
    dp = array([0.113, 0.139, 0.170, 0.210, 0.261, 0.325, 0.400, 0.490])

    vd_err = array([ [0.212, 0.192, 0.209, 0.272, 0.452, 1.2, 1.6, 3.0] , [0.124, 0.153, 0.150, 0.269, 0.371, 0.782, 0.913, 2.123] ])
    dp_err = zeros(8)