function h = pcow(sw, SW, PCOW, varargin)
n = numel(varargin);
if PCOW == 0
    h = 0;
else
    if n == 0
        h = interptable(SW, PCOW, sw);
    else
        SWF = varargin{1};
        PCOWF = varargin{2};
        rpt = varargin{3};
        hm = interptable(SW, PCOW, sw);
        hf = interptable(SWF, PCOWF, sw);
        h = rpt .* hm + ~rpt .* hf;
    end
end