//TODO move this to another place, as ratio test has been taken out and can be used for simplex
override public LinearProgram Solve()
{
int tableauNumber = 0;
bool done = false;
bool answerFound = true;
Console.WriteLine("\nPhase 1 - Table 1");
LinearProgram.DisplayCurrentTable();
//Loops till final table
do
{
tableauNumber++;
int pivotCol = 0;
int pivotRow = 0;
if (RatioTest(out pivotRow, out pivotCol))
{
done = true;
break;
}
CalculateNewCellValues(pivotRow, pivotCol);
//Displays the table
Console.WriteLine("\nTable " + tableauNumber);
LinearProgram.DisplayCurrentTable();
done = true;
answerFound = true;
if (CheckIfContinue())
{
done = false;
answerFound = false;
}
} while (!done);
if (answerFound)
{
PrimalSimplex simplex = new PrimalSimplex(LinearProgram);
LinearProgram = simplex.Solve();
}
//Checks if there is an answer
//TODO Handle the case when there is no solution found, as currently it will display no solution but still return the lp
//if (answerFound == true)
//{
//}
//else
//{
// Console.WriteLine("No Solution");
//}
return(LinearProgram);
}
override public LinearProgram Solve()
{
int tableauNumber = 1;
bool done = false;
bool answerFound = false;
int pivotRow = 0;
int pivotCol = 0;
Console.WriteLine("\nPhase 1 - Table 1");
LinearProgram.DisplayCurrentTable();
//Loops till final table
do
{
tableauNumber++;
pivotRow = 0;
if (RatioTest(out pivotRow, out pivotCol))
{
done = true;
break;
}
CalculateNewCellValues(pivotRow, pivotCol);
Console.WriteLine("\nPhase 1 - Table " + tableauNumber);
LinearProgram.DisplayCurrentTable();
done = true;
answerFound = true;
if (CheckIfContinue())
{
done = false;
answerFound = false;
}
double wRHS = Math.Round(LinearProgram.LinearProgramMatrix[0, LinearProgram.ColumnCount - 1], 10);
//Checks if the W rhs amount is 0
if (wRHS == 0)
{
done = true;
answerFound = true;
}
} while (!done);
//Checks if an answer is found
if (answerFound)
{
//Finds BVs
double[] bvs = LinearProgram.GetBasicVariables();
List <int> bvCols = new List <int>();
for (int i = 0; i < bvs.Length; i++)
{
if (bvs[i] != 0)
{
bvCols.Add(i);
}
}
bool deleteNegatives = false;
//If A is BV, delete Negatives
for (int aCol = 0; aCol < LinearProgram.ColOfA.Count; aCol++)
{
for (int bvCol = 0; bvCol < bvCols.Count; bvCol++)
{
if (LinearProgram.ColOfA[aCol] + 1 == bvCols[bvCol])
{
//Breaks out of outer loop
aCol = LinearProgram.ColOfA.Count;
deleteNegatives = true;
break;
}
}
}
//Deletes the A's
if (Math.Round(LinearProgram.LinearProgramMatrix[0, LinearProgram.ColumnCount - 1], 10) == 0)
{
if (deleteNegatives)
{
for (int i = 0; i < LinearProgram.ColumnCount; i++)
{
if (LinearProgram.LinearProgramMatrix[0, i] < 0)
{
for (int j = 0; j < LinearProgram.RowCount; j++)
{
LinearProgram.LinearProgramMatrix[j, i] = 0;
}
}
}
}
for (int i = 0; i < simplexLP.GetLength(0); i++)
{
for (int j = 0; j < simplexLP.GetLength(1); j++)
{
simplexLP[i, j] = LinearProgram.LinearProgramMatrix[i + 1, j + 1];
}
}
//Sets the Amounts in the A coulmns to 0
foreach (var item in LinearProgram.ColOfA)
{
if (!bvCols.Contains(item + 1))
{
for (int i = 0; i < simplexLP.GetLength(0); i++)
{
simplexLP[i, item] = 0;
}
}
}
LinearProgram.IsTwoPhase = false;
Console.WriteLine("\nPhase 2 - Initial Table");
LinearProgram.LinearProgramMatrix = simplexLP;
LinearProgram.DisplayCurrentTable();
PrimalSimplex simplex = new PrimalSimplex(LinearProgram);
//Calls the appropriate simplex method
LinearProgram = simplex.Solve();
///TODO handle what happens if theres no solution
}
else
{
Console.WriteLine("No Solution");
}
}
//else
//{
// if (pivotRow == 0)
// {
// Console.WriteLine("This LP is unbounded and has no solution");
// }
// Console.WriteLine("No Solution");
//}
return(LinearProgram);
}
//New Main Menu with file,Alg& sensitivity ananlysis selection
public static void Menu()
{
GetInputAndOutputFiles();
//TODO Move this to different place
#region Stuff to Move
List <String> unformatedLP = FileHandler.ReadLP();
foreach (var item in unformatedLP)
{
Console.WriteLine(item);
}
#endregion
bool done = false;
do
{
try
{
Console.WriteLine(@"
IP SOLVER
________________________________________________________
PLEASE SELECT AN ALGORITHM
1.PRIMAL
2.TWO PHASE
3.DUAL
4.BRANCH & BOUND
5.CUTTING PLANE
");
int userinput = int.Parse(Console.ReadLine());
Algorithm menu = (Algorithm)userinput;
switch (menu)
{
case Algorithm.Primal:
linearProgram = new LpFormatter(unformatedLP, Algorithm.Primal).GetLinearProgram();
linearProgram.DisplayCanonicalForm();
PrimalSimplex simplex = new PrimalSimplex(linearProgram);
linearProgram = simplex.Solve();
break;
case Algorithm.TwoPhase:
linearProgram = new LpFormatter(unformatedLP, Algorithm.TwoPhase).GetLinearProgram();
linearProgram.IsTwoPhase = true;
TwoPhase twoPhase = new TwoPhase(linearProgram);
linearProgram.DisplayCanonicalForm();
linearProgram = twoPhase.Solve();
break;
case Algorithm.Dual:
linearProgram = new LpFormatter(unformatedLP, Algorithm.Dual).GetLinearProgram();
linearProgram.DisplayCanonicalForm();
Dual dual = new Dual(linearProgram);
linearProgram = dual.Solve();
break;
case Algorithm.BranchAndBound:
linearProgram = new LpFormatter(unformatedLP, Algorithm.Dual).GetLinearProgram();
linearProgram.DisplayCanonicalForm();
Dual bbDual = new Dual(linearProgram);
linearProgram = bbDual.Solve();
BranchAndBound BB = new BranchAndBound(linearProgram);
linearProgram = BB.Solve();
break;
case Algorithm.CuttingPlane:
linearProgram = new LpFormatter(unformatedLP, Algorithm.Dual).GetLinearProgram();
linearProgram.DisplayCanonicalForm();
Dual cutDual = new Dual(linearProgram);
linearProgram = cutDual.Solve();
CuttingPlane cutingPlane = new CuttingPlane(linearProgram);
linearProgram = cutingPlane.Solve();
break;
default:
break;
}
//todo check for input errors, set done to false if there arent any
done = true;
}
catch (FormatException)
{
done = false;
Console.WriteLine("Invalid Input");
}
} while (!done);
if (LpTools.CheckIfIPIsSolved(linearProgram))
{
linearProgram.DisplaySolution();
}
else
{
Console.WriteLine("No Solution!");
Console.ReadKey();
}
Console.Clear();
if (LpTools.CheckIfIPIsSolved(linearProgram))
{
do
{
SensitivityAnalysisMenu();
} while (true);
}
}