def calculate_markedness(PPV, NPV):
    """
    Calculates the markedness meassure of the supplied data, using the equation as per: http://www.flinders.edu.au/science_engineering/fms/School-CSEM/publications/tech_reps-research_artfcts/TRRA_2007.pdf (page 5)
        Markedness = PPV+NPV-1
            
    Input:
        PPV: Positive Prediction Value
        NPV: Negative Pediction Value

    Output:
        Markedness
    """
    
    return PPV+NPV-1