Documentation of objvrp

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Function Synopsis

[ObjVal, VRPData, VRPResult] = objvrp(Routes, VRPData)

Help text

 OBJective function for the vehicle routing problem

 This function provides the objective function for Vehicle 
 routing problems (VRP). A number of examples are provided, 
 see vrpgetdata for the data definition of the problem 
 specific information.
 This function computes the length/cost of the routes given by the
 individuals. The variables of the individuals define the order
 of the points to travel for each of the used vehicles. 
 The format of the route coding in the individuals is described 
 in vrpconvind.
 Beside the maximum load time windows may also used.

 Syntax: ObjVal = objvrp(Routes, VRPData)

 Input parameter:
    Routes   - Matrix containg the variables of the individuals 
               (the points of the routes).
               The exact format of the coding of the routes and multiple 
               vehicles is described in vrpconvind (where the conversion 
               from individuals to routes is done)
    VRPData  - Structure containg problem specific data for the current VRP
               or a string with name of VRP
               see vrpgetdata for more info on names of VRPData elements 
               and supported examples

 Output parameter:
    ObjVal   - Matrix containing the objective values for the individuals
               in Routes (length/cost of the routes).
               elseif Routes == [NaN, NaN, xx], than see objfun1 for options

 See also: demovrp, plotvrp, vrpconvind, vrpgetdata, tbxperm, initpp, mutswap, mutexch, recgp, recpm

Cross-Reference Information

Listing of function objvrp

% Author:   Hartmut Pohlheim
% History:  28.05.2005  file created


function [ObjVal, VRPData, VRPResult] = objvrp(Routes, VRPData)

   NAIN = nargin; NAOUT = nargout;

   if NAIN < 1, Routes = []; end
   if isnan(Routes), Routes = []; end
   if isempty(Routes), Routes = [NaN, NaN, 1]; end
   
   if NAIN < 2, VRPData = []; end
   if isempty(VRPData), VRPData = 'vrpnc1'; end
   
   if ischar(VRPData), VRPData = vrpgetdata(VRPData); end
   
   % Check VRPData for structure, return if not a structure
   if ~(isstruct(VRPData)),
      warning(sprintf('Problem specific vehicle routing problem data are needed. Please provide them as input parameter to %s', mfilename));
      ObjVal = Inf * ones(size(Routes,1)); return;
   end
   
   % Number of customers (XYData - depot)
   NumCustomer = size(VRPData.XYData,1) - 1;
   % Dimension of objective function (number of customers + max number of vehicles)
   Dim = NumCustomer + VRPData.MaxVehicle;

   % create structure
   if isnan(Routes(1)),
      if all([isnan(Routes(2)), Routes(3) <= 10]),
         ObjVal = objfunoptset(...
             'FunctionName', sprintf('Vehicle Routing (%s)', VRPData.FunName), ...
             'VarBoundMin',   1, 'VarBoundMax', Dim, ...
             'NumVarDefault', Dim, 'NumVarMin', Dim, 'NumVarMax', Dim, ...
             'NumObjDefault', 1, 'NumObjMin',   1, 'NumObjMax', 1, ...
             'GlobalMinObjV', VRPData.BestCost);
      elseif Routes(3) == 11,
         NOBJUSE = Routes(4);
      end
   else
      % Get number of routes and their length
      [Nroutes, Lroute] = size(Routes);

      % Calculate the distance of each route
      dist = zeros(Nroutes, 1);
      VRPResult.RouteCost = {};
      for irout = 1:Nroutes,
         % Convert the individuals into routes (as needed by rteTC and pplot)
         rte = vrpconvind('ind2route', Routes(irout,:), VRPData);
         % Calculate the cost of the routes (and further data, when requested by i.e. plot function)
         if nargout > 1,
            [TC, XFlg, out] = rteTC(rte, VRPData.Dists, {VRPData.Demand, VRPData.MaxLoad}, {VRPData.LoadTime, VRPData.TimeWindow}, {'maxTCfeas', VRPData.MaxCost});
         else
            [TC] = rteTC(rte, VRPData.Dists, {VRPData.Demand, VRPData.MaxLoad}, {VRPData.LoadTime, VRPData.TimeWindow}, {'maxTCfeas', VRPData.MaxCost});
         end
         % Objective value is (currently) the sum of the cost of all routes
         % Here we might also use multiple objectives, but I am not sure, if this is really usefull
         ObjVal(irout,1) = sum(TC);
         % Put the route and the cost of each route into the result structure
         VRPResult.RouteOrder{irout,1} = rte;
         VRPResult.RouteCost{irout,1} = TC';
      end
      
   end
   

% End of function