public LPSolution Solve()
{
LinearProgram.VerifyVariables();
Tableau previousTableau = new Tableau();
ConstraintRow[] constraints = new ConstraintRow[LinearProgram.Constraints.Length];
for (int i = 0; i < constraints.Length; i++)
{
constraints[i] = new ConstraintRow(i, constraints.Length, LinearProgram.Constraints[i].GetVars(), LinearProgram.Constraints[i].Constant);
}
previousTableau.Constraints = constraints;
previousTableau.ObjectiveRow = new ObjectiveRow(constraints.Length, LinearProgram.ObjectiveFunction.GetVars());
Variable[] emptyVars = previousTableau.ObjectiveRow.Vars.Where(var => !var.IsSlack).Select(var => var.Empty).ToArray();
Tableau currentTableau = Tableau.EmptyTableau(previousTableau.Constraints.Length, emptyVars);
while (MostNegitive(previousTableau, out Variable mostNegitive))
{
int index = 0;
double leastPositive = previousTableau.Constraints.Length > 0 ? previousTableau.Constraints[index].RatioTest(mostNegitive) : -1;
for (int i = 0; i < previousTableau.Constraints.Length; i++)
{
double rt = previousTableau.Constraints[i].RatioTest(mostNegitive);
if (rt > 0 && rt < leastPositive)
{
leastPositive = rt; index = i;
}
}
if (leastPositive == 0)
{
throw new Exception("Least Positive is Unchanged");
}
currentTableau.Constraints[index] = previousTableau.Constraints[index].PivotRow(mostNegitive.Index);
currentTableau.ObjectiveRow = previousTableau.ObjectiveRow.Normalize(mostNegitive.Index, currentTableau.Constraints[index].Vars, currentTableau.Constraints[index].RHS);
for (int i = 0; i < currentTableau.Constraints.Length; i++)
{
if (i != index)
{
currentTableau.Constraints[i] = previousTableau.Constraints[i].Normalize(mostNegitive.Index, currentTableau.Constraints[index].Vars, currentTableau.Constraints[index].RHS);
}
}
previousTableau = currentTableau.Copy();
currentTableau = Tableau.EmptyTableau(previousTableau.Constraints.Length, emptyVars);
}
Console.WriteLine(previousTableau);
return(new LPSolution(previousTableau));
}
public Tableau Copy()
{
ConstraintRow[] constraintRow = new ConstraintRow[Constraints.Length];
Constraints.CopyTo(constraintRow, 0);
return(new Tableau()
{
Constraints = constraintRow, ObjectiveRow = new ObjectiveRow()
{
Vars = new List <Variable>(ObjectiveRow.Vars).ToArray(), RHS = ObjectiveRow.RHS
}
});
}
public static Tableau EmptyTableau(int constraintCount, Variable[] emptyVariables)
{
ConstraintRow[] constraints = new ConstraintRow[constraintCount];
for (int i = 0; i < constraints.Length; i++)
{
constraints[i] = new ConstraintRow(i, constraintCount, new List <Variable>(emptyVariables).ToArray(), 0);
}
return(new Tableau()
{
Constraints = constraints, ObjectiveRow = new ObjectiveRow(constraints.Length, new List <Variable>(emptyVariables).ToArray())
});
}
public static ConstraintRowParser Create(Constraint constraint)
{
if (constraint == null || constraint.ElementaryConstraints.Length == 0)
{
return(null);
}
ConstraintRowParser constraintRowParser = new ConstraintRowParser();
System.Action <ConstraintRow[], ElementaryConstraint, int, int> AssignRow = (rows, ec, constraintRow, localRow) =>
{
if (rows[constraintRow] != null)
{
throw new Exception("Row index " + constraintRow + " already assigned: " + rows[constraintRow].ElementaryConstraint.NativeName);
}
rows[constraintRow] = new ConstraintRow(ec, localRow);
};
ElementaryConstraint[] ordinaryElementaryConstraints = constraint.GetOrdinaryElementaryConstraints();
foreach (ElementaryConstraint ec in ordinaryElementaryConstraints)
{
if (ec.NumRows > 1)
{
// Only rotational QuatLock ("QL") and translational SphericalRel ("SR") with three rows.
ConstraintRow[] rows = ec.NativeName == "QL" ? constraintRowParser.RotationalRows :
ec.NativeName == "SW" ? constraintRowParser.RotationalRows :
ec.NativeName == "SR" ? constraintRowParser.TranslationalRows :
null;
if (rows == null)
{
throw new Exception("Unknown elementary constraint with name: " + ec.NativeName);
}
// For Swing we should assign rows 0 and 1.
for (int row = 0; row < ec.NumRows; ++row)
{
AssignRow(rows, ec, row, row);
}
}
else if (ec.NumRows == 1)
{
// Dot2 for single translational row ("D2_U" along U and "D2_V" along V).
int translationalRow = ec.NativeName == "D2_U" ? 0 :
ec.NativeName == "D2_V" ? 1 :
ec.NativeName == "D2_N" ? 2 :
ec.NativeName == "CN" ? 2 :
-1;
// Dot1 for single rotational row ("D1_VN" about U and "D1_UN" about V ).
int rotationalRow = ec.NativeName == "D1_VN" ? 0 :
ec.NativeName == "D1_UN" ? 1 :
ec.NativeName == "D1_UV" ? 2 :
-1;
if (translationalRow < 0 && rotationalRow < 0)
{
throw new Exception("Unknown single row elementary constraint with name: " + ec.NativeName);
}
if (translationalRow >= 0)
{
AssignRow(constraintRowParser.TranslationalRows, ec, translationalRow, 0);
}
else
{
AssignRow(constraintRowParser.RotationalRows, ec, rotationalRow, 0);
}
}
}
return(constraintRowParser);
}
