draught adjustment factor pseudocode

draught_adjustment_factor_pseudocode.py

def draught_adjustment_factor(hour_slice_of_ais_ts):
    # #
    # 
    # Things we are missing:
    # - DraughtRatio for ballasted ship (DRb)
    # - DraughtRatio for loaded ship (DRl)
    # - DraughtRatio for non-ballasted ship (DRnbs)
    # Are these in IHS Fairplay? 
    # Cannot see where they come from, or how they are computed.
    #
    
    # #
    #
    # Things we can compute:
    # - assign AIS time series ballast/loaded labels pr voyage
    # - percentage of ballast voyages (Pb)
    # - percentage of loaded voyages (Pl)
    # 
    
    # Draught Adjustmen Factor - non ballast ships  
    DAFnbs = (
        # Draught Ratio - non-ballasted ships
        DRnbs ** (2/3)
    )

    # Draught Adjustment Factor - ballasted ship
    DAFbs = (
        # DRb = draught ratio for ballasted ships during ballast condition
        # Pb =  percentage of ballast voyage annually for ballasted ships
        (DRb ** (2/3) * Pb)
        +
        # DRl = draught ratio for ballasted ships during loaded condition
        # Pl = percentage of loaded voyage annually for ballasted ships
        (DRl ** (2/3) * Pl)
    )
    
    if (hour_slice_of_ais_ts.ballast == True):
        return DAFbs
    else:
        return DAFnbs