def pMorphIa( morphology ):
    """ P(D|Ia) : The probability that one would observe
    a SN host galaxy to have the given morphology, assuming 
    that the SN is of type Ia 

    Morphology may be specified as a hubble type :
      [ 'E', 'S0', 'Sa', 'Sb', 'Sbc', 'Sc', 'Scd', 'Irr' ]
    or using the CANDELS visual classification metrics 
    for spheroid/disk/irregular and mixed morphologies : :
      [ 's', 'sd',  'd', 'di', 'i' ]

    RETURNS :  P(D|Ia), errPplus, errPminus
    """
    if morphology   == 'E'  : return( 0.141, 0.021, -0.018 ) 
    elif morphology == 'S0' : return( 0.217, 0.026, -0.023 )
    elif morphology == 'Sa' : return( 0.149, 0.022, -0.019 )
    elif morphology == 'Sb' : return( 0.177, 0.023, -0.021 )
    elif morphology == 'Sbc': return( 0.117, 0.019, -0.017 )
    elif morphology == 'Sc' : return( 0.120, 0.019, -0.017 )
    elif morphology == 'Scd': return( 0.076, 0.016, -0.013 )
    elif morphology == 'Irr': return( 0.003, 0.004, -0.002 )

    elif morphology == 's'  : return( 0.253, 0.028, -0.025 ) 
    elif morphology == 'sd' : return( 0.255, 0.028, -0.025 )
    elif morphology == 'd'  : return( 0.353, 0.032, -0.030 )
    elif morphology == 'di' : return( 0.103, 0.018, -0.015 )   
    elif morphology == 'i'  : return( 0.035, 0.011, -0.009 )
    elif morphology == 'u'  : return( 1, 0.1, -0.1 )
    else : return( 1, 0.1, -0.1 )