apis/examples_matlab_control/transport__gdx_8m_source.html

function transport_gdx(varargin)


    % check workspace info from arguments

    if nargin > 0

        wsInfo = gams.control.WorkspaceInfo();

        wsInfo.systemDirectory = varargin{1};

        ws = gams.control.Workspace(wsInfo);

    else

        ws = gams.control.Workspace();

    end


    % prepare input data

    plants = {'Seattle', 'San-Diego'};

    markets = {'New-York', 'Chicago', 'Topeka'};

    capacity = containers.Map();

    capacity('Seattle') = 350;

    capacity('San-Diego') = 600;

    demand = containers.Map();

    demand('New-York') = 325;

    demand('Chicago') = 300;

    demand('Topeka') = 275;

    distance = containers.Map();

    distance('Seattle.New-York') = 2.5;

    distance('Seattle.Chicago') = 1.7;

    distance('Seattle.Topeka') = 1.8;

    distance('San-Diego.New-York') = 2.5;

    distance('San-Diego.Chicago') = 1.8;

    distance('San-Diego.Topeka') = 1.4;


    % add a database and add input data into the database

    db = ws.addDatabase();


    i = db.addSet('i', 1, 'canning plants');

    for p = plants

        i.addRecord(p{1});

    end


    j = db.addSet('j', 1, 'markets');

    for m = markets

        j.addRecord(m{1});

    end


    a = db.addParameter('a', 'capacity of plant i in cases', i);

    for p = plants

        rec = a.addRecord(p{1});

        rec.value = capacity(p{1});

    end


    b = db.addParameter('b', 'demand at market j in cases', j);

    for m = markets

        rec = b.addRecord(m{1});

        rec.value = demand(m{1});

    end


    d = db.addParameter('d', 'distance in thousands of miles', i, j);

    for p = plants

        for m = markets

            rec = d.addRecord(p{1}, m{1});

            rec.value = distance([p{1}, '.', m{1}]);

        end

    end


    f = db.addParameter('f', 'freight in dollars per case per thousand miles');

    rec = f.addRecord();

    rec.value = 90;


    % export the Database to a GDX file with name 'data.gdx' located in the 'workingDirectory' of the Workspace

    db.export('data.gdx');


    % add a new Database and initialize it from the GDX file just created

    gdxdb = ws.addDatabaseFromGDX('data.gdx');


    % read symbol data from the database and fill them into Matlab data structures

    gdxPlants = {};

    for rec = gdxdb.getSet('i').records

        gdxPlants{end+1} = rec{1}.key(1);

    end


    gdxMarkets = {};

    for rec = gdxdb.getSet('j').records

        gdxMarkets{end+1} = rec{1}.key(1);

    end


    gdxCapacity = containers.Map();

    for rec = gdxdb.getParameter('a').records

        gdxCapacity(rec{1}.key(1)) = rec{1}.value;

    end


    gdxDemand = containers.Map();

    for rec = gdxdb.getParameter('b').records

        gdxDemand(rec{1}.key(1)) = rec{1}.value;

    end


    gdxDistance = containers.Map();

    for rec = gdxdb.getParameter('d').records

        gdxDistance([rec{1}.key(1), '.', rec{1}.key(2)]) = rec{1}.value;

    end


    gdxFreight = gdxdb.getParameter('f').record.value;


    % print out data read from GDX file

    fprintf('Data read from data.gdx\n');

    fprintf('Set i: %s\n', gdxdb.getSet('i').text);

    for p = gdxPlants

        fprintf('  %s\n', p{1});

    end


    fprintf('Set j: %s\n', gdxdb.getSet('j').text);

    for m = gdxMarkets

        fprintf('  %s\n', m{1});

    end


    fprintf('Parameter a: %s\n', gdxdb.getParameter('a').text);

    for a = keys(gdxCapacity)

        fprintf('  %s: %g\n', a{1}, gdxCapacity(a{1}));

    end


    fprintf('Parameter b: %s\n', gdxdb.getParameter('b').text);

    for b = keys(gdxDemand)

        fprintf('  %s: %g\n', b{1}, gdxDemand(b{1}));

    end


    fprintf('Parameter d: %s\n', gdxdb.getParameter('d').text);

    for d = keys(gdxDistance)

        fprintf('  %s: %g\n', d{1}, gdxDistance(d{1}));

    end


    fprintf('Scalar f: %s\n  %g\n', gdxdb.getParameter('f').text, gdxFreight);

end