compute_fr_flows(densities, flows, celldata, outflow, ts)

function frf = compute_fr_flows(densities, flows, celldata, outflow, ts)
% COMPUTE_FR_FLOWS - compute off-ramp flow values from the vector of flows
%                    and off-ramp split-ratio data.
%
% Call:   frf = compute_fr_flows(densities, flows, celldata, outflow, ts)
%
% Parameters:
%             densities - vector of densities;
%             flows     - vector of flows, must have the same size as 'densities';
%             celldata - array of freeway cell data structures, whose length
%                        must be the same as the size of 'flows' vector;
%             outflow  - how much can be allowed through the right boundary;
%             ts       - sampling period.
%
%
% Returns:   frf - array of off-ramp flows.
%
% Last modified:   09/14/2006.

%
% Alex Kurzhanskiy   <[e-mail]>
%

M = size(flows, 1);
N = size(celldata, 2);  % number of cells

if M ~= N
  error('COMPUTE_FR_FLOWS: number of cells does not match number of flows.');
end

frf = [];

for i = 1:N
  if i == N
    f = get_rbflow(densities(N, 1), flows(N, 1), celldata(N), outflow, ts);
    f = celldata(N).FRbeta * f;
  else
    if celldata(i).FRbeta < 1
      f = (celldata(i).FRbeta / (1 - celldata(i).FRbeta)) * flows(i+1, 1);
    else
      l = abs(celldata(i).PMend - celldata(i).PMstart);  % cell length
      v = celldata(i).FDfmax / celldata(i).FDrhocrit;  % free-flow speed
      n = densities(i, 1) * l;  % number of vehicles
      r = celldata(i).ORgamma * celldata(i).ORflow * ts;  % number of vehicles from on-ramp
      f = (v/l) * (n + r);
    end
  end
  frf = [frf; min([celldata(i).FRfmax f])];
end

return;