/// <summary>
/// Initially formulate the model as an LP
/// Solve the LP model. If the model is solved to an optimal result,
/// find the duals of the constraints. FindNewPattern() method uses duals and
/// tries to find a new pattern. If a new pattern is found, it is added to the PatternRolls data.
/// This model keeps on growing if there is a new pattern found in the FindNewPattern() method
/// and resolved. This process continues until there is no new pattern
/// </summary>
/// <returns>Returns true if an optimal solution is found, otherwise false</returns>
public bool SolveMasterModel()
{
SetCurrentToMaster(Domain.RealNonnegative);
Model masterModel = _context.CurrentModel;
SimplexDirective simplex = new SimplexDirective();
simplex.GetSensitivity = true; //setting this to true, generates shadow prices, needed to calc new pattern
Solution sol = _context.Solve(simplex);
//Check if the solution is optimal
if (sol.Quality == SolverQuality.Optimal)
{
Report report = sol.GetReport(ReportVerbosity.All);
//LinearReport has the Sensitivity report
LinearReport lpReport = report as LinearReport;
//Copying the duals from lpReport.GetShadowPrices
//This is needed to match indexes (Roll Widths) in the SetRoll. For example: GetShadowPrices returns the keys as DemandConstraint(12),
//but keys should just be 12 to match the indexes
//Currently a limitation with our API
//https://ideas.repec.org/p/fth/nesowa/96-18.html
_shadowPrices.Clear();
foreach (KeyValuePair <string, Rational> pair in lpReport.GetShadowPrices(masterModel.Constraints.First()))
{
_shadowPrices.Add(new KeyValuePair <int, Rational>(GetIndexFromName(pair.Key), pair.Value));
}
//we have defined a single decision with multiple values (how many cuts per pattern to reach demanded rolls)
var goal = masterModel.Goals.First().ToDouble();
PrintSolution(masterModel.Decisions.First().GetValues(), goal, false);
//Console.WriteLine();
//Console.WriteLine("Now totalRolls required to meet the demand:{0}", masterModel.Goals.First().ToDouble());
//Console.WriteLine();
return(true);
}
return(false);
}
private void Solv_Click(object sender, EventArgs e)
{
//Coded by : Mohammed Al Sayed
//Zagzig university ,Group B section 13
if (Objtxt.Text == "")
{
MessageBox.Show("Please Enter The Object Function", "Error",
MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return;
}
try
{
Objtxt.Text = Objtxt.Text.ToLower().TrimEnd(Environment.NewLine.ToCharArray());//triming newline at the end
string objectfunction = Objtxt.Text;
//begin Setting object function
Model model = context.CreateModel();//Creating Linear Programming Model
for (int i = 0; i < objectfunction.Length; i++)
{ //extracting Variables and adding decisions
if (char.IsNumber(objectfunction[i]) && char.IsLetter(objectfunction[i + 1]))
{
objectfunction = objectfunction.Insert(i + 1, "*");//Parsing text into an acceptable Term like 2*x+3*y >> 2x become 2*x
}
else if (char.IsLetter(objectfunction[i]))
{
//Adding Decisions(Variables) into model
model.AddDecision(new Decision(Domain.RealNonnegative, objectfunction[i].ToString()));//each literal represent a variable
}
}
//end setting object function
//begin SettingConstrains
if (Cnstrntxt.Text == "")
{
MessageBox.Show("Please Enter The Constrains", "Error",
MessageBoxButtons.OK, MessageBoxIcon.Exclamation); return;
}
Cnstrntxt.Text = Cnstrntxt.Text.ToLower().TrimEnd(Environment.NewLine.ToCharArray()); //removing newline at the end of the text
string constrainsRaw = Cnstrntxt.Text;
//parsing text into an acceptable MOL term ,, something like that 2*x+4*y a programatic equation
for (int i = 0; i < constrainsRaw.Length - 1; i++)
{
if (char.IsNumber(constrainsRaw[i]) && char.IsLetter(constrainsRaw[i + 1])) //2X
{
constrainsRaw = constrainsRaw.Insert(i + 1, "*"); //2*x
}
}
//spliting constrains
string[] constrains = constrainsRaw.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries);
for (int i = 0; i <= constrains.GetUpperBound(0); i++)
{
model.AddConstraint("Constrain_" + i.ToString(), constrains[i]);//each line represent a constrain
}
//end setting constrains
//begin setting goal
GoalKind goal; //defining a goal
if (tpcom.SelectedIndex == 1) //goal type
{
goal = GoalKind.Minimize;
}
else
{
goal = GoalKind.Maximize;
}
model.AddGoal("target", goal, objectfunction);
//end setting goal
//begin solving
SimplexDirective simplxReactor = new SimplexDirective(); ///solver object
if (Chksensitivity.Checked)
{
simplxReactor.GetSensitivity = true; //sensitivity
}
if (ChkInfeasibility.Checked)
{
simplxReactor.GetInfeasibility = true; //infeasibility
}
if (cmbAlgorithm.SelectedIndex == 1)
{
simplxReactor.Algorithm = SimplexAlgorithm.Dual; //Algorithm used
}
Solution solution = context.Solve(simplxReactor);
Report report = solution.GetReport(); //defining a report
if (ChkFullReport.Checked)
{
txtreport.Text = report.ToString(); //presenting the report in report textbox
}
ResultTextbox.Text = ""; //removing old values if existed
ResultTextbox.Text = solution.Goals.First().ToDouble().ToString();
VarResultTextbox.Text = "";
foreach (Decision d in model.Decisions) //adding decisions(variables) and they production size in variable textbox
{
VarResultTextbox.Text += d.Name + " = " + d.ToString() + Environment.NewLine;
}
//Duals aka shadow prices
if (chkdual.Checked)
{
txtdual.Text = ""; //removing old values if existed
LinearReport lin = ((LinearReport)solution.GetReport()); //generating a linear programming report out of the solution report
foreach (Microsoft.SolverFoundation.Services.Constraint constraint in model.Constraints) //getting constrains from the model
{
foreach (var dual in lin.GetShadowPrices(constraint)) //getting the shadow prices for each constrain
{
txtdual.Text += dual.Key + " = " + dual.Value.ToDouble().ToString() + Environment.NewLine;
}
}
}
//end shadowprices
//begin Sensitivity Analysis
if (Chksensitivity.Checked)
{
txtbound.Text = ""; //removing old values if existed
LinearReport lin = ((LinearReport)solution.GetReport()); //generating a linear programming report out of the solution report
foreach (Microsoft.SolverFoundation.Services.Constraint constraint in model.Constraints) //getting constrains from the model
{
foreach (var bound in lin.GetConstraintBoundsSensitivity(constraint)) //getting the boundaries prices for each constrain
{
//parsing the boundaries into intervals
//opening the interval if infinity existed
txtbound.Text += bound.Key + " = " + bound.Value.Current.ToDouble().ToString() + Environment.NewLine +
(Double.IsInfinity(bound.Value.Lower.ToDouble()) ? "]" : "[") + bound.Value.Lower.ToDouble().ToString() + " , " + bound.Value.Upper.ToDouble().ToString() + (Double.IsInfinity(bound.Value.Upper.ToDouble()) ? "[" : "]")
+ Environment.NewLine + Environment.NewLine
;
}
}
}
context.ClearModel();//killing the model object so we can create a new one
//end solving
//begin handling errors
}
catch (Exception ex)
{
context.ClearModel();
txtreport.Text = "An Error have occured If you're sure about you entries "
+ "Please Send this report to the programmer" + Environment.NewLine + Environment.NewLine;
txtreport.Text += Objtxt.Text + Environment.NewLine + Environment.NewLine;
txtreport.Text += Cnstrntxt.Text + Environment.NewLine + Environment.NewLine;
txtreport.Text += ex.Message;
txtreport.ForeColor = Color.Red;
MessageBox.Show("Error,Please Check your entries" + Environment.NewLine + Environment.NewLine + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
tabControl1.SelectedIndex = 1;
//end handling errors
}
