private static void ThreadProc(object filename)
{
using (var lp = LpSolve.read_LP((string)filename, 0, ""))
{
lpsolve_return ret = lp.solve();
double o = lp.get_objective();
Debug.Assert(ret == lpsolve_return.OPTIMAL && Math.Round(o, 13) == 1779.4810350637485);
}
}
private static int Demo()
{
// We will build the model row by row
// So we start with creating a model with 0 rows and 2 columns
int Ncol = 2; // there are two variables in the model
using (LpSolve lp = LpSolve.make_lp(0, Ncol))
{
if (lp == null)
{
return(1); // couldn't construct a new model...
}
//let us name our variables. Not required, but can be useful for debugging
lp.set_col_name(1, "x");
lp.set_col_name(2, "y");
//create space large enough for one row
int[] colno = new int[Ncol];
double[] row = new double[Ncol];
// makes building the model faster if it is done rows by row
lp.set_add_rowmode(true);
int j = 0;
//construct first row (120 x + 210 y <= 15000)
colno[j] = 1; // first column
row[j++] = 120;
colno[j] = 2; // second column
row[j++] = 210;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.LE, 15000) == false)
{
return(3);
}
//construct second row (110 x + 30 y <= 4000)
j = 0;
colno[j] = 1; // first column
row[j++] = 110;
colno[j] = 2; // second column
row[j++] = 30;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.LE, 4000) == false)
{
return(3);
}
//construct third row (x + y <= 75)
j = 0;
colno[j] = 1; // first column
row[j++] = 1;
colno[j] = 2; // second column
row[j++] = 1;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.LE, 75) == false)
{
return(3);
}
//rowmode should be turned off again when done building the model
lp.set_add_rowmode(false);
//set the objective function (143 x + 60 y)
j = 0;
colno[j] = 1; // first column
row[j++] = 143;
colno[j] = 2; // second column
row[j++] = 60;
if (lp.set_obj_fnex(j, row, colno) == false)
{
return(4);
}
// set the object direction to maximize
lp.set_maxim();
// just out of curioucity, now show the model in lp format on screen
// this only works if this is a console application. If not, use write_lp and a filename
lp.write_lp("model.lp");
// I only want to see important messages on screen while solving
lp.set_verbose(3);
// Now let lpsolve calculate a solution
lpsolve_return s = lp.solve();
if (s != lpsolve_return.OPTIMAL)
{
return(5);
}
// a solution is calculated, now lets get some results
// objective value
Debug.WriteLine("Objective value: " + lp.get_objective());
// variable values
lp.get_variables(row);
for (j = 0; j < Ncol; j++)
{
Debug.WriteLine(lp.get_col_name(j + 1) + ": " + row[j]);
}
}
return(0);
} //Demo
private static void Test()
{
const string NewLine = "\n";
double[] Row;
double[] Lower;
double[] Upper;
double[] Col;
double[] Arry;
using (var lp = LpSolve.make_lp(0, 4))
{
Version version = LpSolve.LpSolveVersion;
/* let's first demonstrate the logfunc callback feature */
lp.put_logfunc(logfunc, IntPtr.Zero);
lp.print_str("lp_solve " + version + " demo" + NewLine + NewLine);
lp.solve(); /* just to see that a message is send via the logfunc routine ... */
/* ok, that is enough, no more callback */
lp.put_logfunc(null, IntPtr.Zero);
/* Now redirect all output to a file */
lp.set_outputfile("result.txt");
/* set an abort function. Again optional */
lp.put_abortfunc(ctrlcfunc, IntPtr.Zero);
/* set a message function. Again optional */
lp.put_msgfunc(msgfunc, IntPtr.Zero, lpsolve_msgmask.MSG_PRESOLVE | lpsolve_msgmask.MSG_LPFEASIBLE | lpsolve_msgmask.MSG_LPOPTIMAL | lpsolve_msgmask.MSG_MILPEQUAL | lpsolve_msgmask.MSG_MILPFEASIBLE | lpsolve_msgmask.MSG_MILPBETTER);
lp.print_str("lp_solve " + version + " demo" + NewLine + NewLine);
lp.print_str("This demo will show most of the features of lp_solve " + version + NewLine);
lp.print_str(NewLine + "We start by creating a new problem with 4 variables and 0 constraints" + NewLine);
lp.print_str("We use: lp = LpSolve.make_lp(0, 4);" + NewLine);
lp.set_timeout(0);
lp.print_str("We can show the current problem with lp.print_lp();" + NewLine);
lp.print_lp();
lp.print_str("Now we add some constraints" + NewLine);
lp.print_str("lp.add_constraint(Row, lpsolve_constr_types.LE, 4);" + NewLine);
// pay attention to the 1 base and ignored 0 column for constraints
lp.add_constraint(new double[] { 0, 3, 2, 2, 1 }, lpsolve_constr_types.LE, 4);
lp.print_lp();
// check ROW array works
Row = new double[] { 0, 0, 4, 3, 1 };
lp.print_str("lp.add_constraint(Row, lpsolve_constr_types.GE, 3);" + NewLine);
lp.add_constraint(Row, lpsolve_constr_types.GE, 3);
lp.print_lp();
lp.print_str("Set the objective function" + NewLine);
lp.print_str("lp.set_obj_fn(Row);" + NewLine);
lp.set_obj_fn(new double[] { 0, 2, 3, -2, 3 });
lp.print_lp();
lp.print_str("Now solve the problem with lp.solve();" + NewLine);
lp.print_str(lp.solve() + ": " + lp.get_objective() + NewLine);
Col = new double[lp.get_Ncolumns()];
lp.get_variables(Col);
Row = new double[lp.get_Nrows()];
lp.get_constraints(Row);
Arry = new double[lp.get_Ncolumns() + lp.get_Nrows() + 1];
lp.get_dual_solution(Arry);
Arry = new double[lp.get_Ncolumns() + lp.get_Nrows()];
Lower = new double[lp.get_Ncolumns() + lp.get_Nrows()];
Upper = new double[lp.get_Ncolumns() + lp.get_Nrows()];
lp.get_sensitivity_rhs(Arry, Lower, Upper);
Lower = new double[lp.get_Ncolumns() + 1];
Upper = new double[lp.get_Ncolumns() + 1];
lp.get_sensitivity_obj(Lower, Upper);
lp.print_str("The value is 0, this means we found an optimal solution" + NewLine);
lp.print_str("We can display this solution with lp.print_solution();" + NewLine);
lp.print_objective();
lp.print_solution(1);
lp.print_constraints(1);
lp.print_str("The dual variables of the solution are printed with" + NewLine);
lp.print_str("lp.print_duals();" + NewLine);
lp.print_duals();
lp.print_str("We can change a single element in the matrix with" + NewLine);
lp.print_str("lp.set_mat(2, 1, 0.5);" + NewLine);
lp.set_mat(2, 1, 0.5);
lp.print_lp();
lp.print_str("If we want to maximize the objective function use lp.set_maxim();" + NewLine);
lp.set_maxim();
lp.print_lp();
lp.print_str("after solving this gives us:" + NewLine);
lp.solve();
lp.print_objective();
lp.print_solution(1);
lp.print_constraints(1);
lp.print_duals();
lp.print_str("Change the value of a rhs element with lp.set_rh(1, 7.45);" + NewLine);
lp.set_rh(1, 7.45);
lp.print_lp();
lp.solve();
lp.print_objective();
lp.print_solution(1);
lp.print_constraints(1);
lp.print_str("We change C4 to the integer type with" + NewLine);
lp.print_str("lp.set_int(4, true);" + NewLine);
lp.set_int(4, true);
lp.print_lp();
lp.print_str("We set branch & bound debugging on with lp.set_debug(true);" + NewLine);
lp.set_debug(true);
lp.print_str("and solve..." + NewLine);
lp.solve();
lp.print_objective();
lp.print_solution(1);
lp.print_constraints(1);
lp.print_str("We can set bounds on the variables with" + NewLine);
lp.print_str("lp.set_lowbo(2, 2); & lp.set_upbo(4, 5.3);" + NewLine);
lp.set_lowbo(2, 2);
lp.set_upbo(4, 5.3);
lp.print_lp();
lp.solve();
lp.print_objective();
lp.print_solution(1);
lp.print_constraints(1);
lp.print_str("Now remove a constraint with lp.del_constraint(1);" + NewLine);
lp.del_constraint(1);
lp.print_lp();
lp.print_str("Add an equality constraint" + NewLine);
Row = new double[] { 0, 1, 2, 1, 4 };
lp.add_constraint(Row, lpsolve_constr_types.EQ, 8);
lp.print_lp();
lp.print_str("A column can be added with:" + NewLine);
lp.print_str("lp.add_column(Col);" + NewLine);
lp.add_column(new double[] { 3, 2, 2 });
lp.print_lp();
lp.print_str("A column can be removed with:" + NewLine);
lp.print_str("lp.del_column(3);" + NewLine);
lp.del_column(3);
lp.print_lp();
lp.print_str("We can use automatic scaling with:" + NewLine);
lp.print_str("lp.set_scaling(lpsolve_scale_algorithm.SCALE_MEAN, lpsolve_scale_parameters.SCALE_NONE);" + NewLine);
lp.set_scaling(lpsolve_scale_algorithm.SCALE_MEAN, lpsolve_scale_parameters.SCALE_NONE);
lp.print_lp();
lp.print_str("The function lp.get_mat(row, column); returns a single" + NewLine);
lp.print_str("matrix element" + NewLine);
lp.print_str("lp.get_mat(2, 3); lp.get_mat(1, 1); gives " + lp.get_mat(2, 3) + ", " + lp.get_mat(1, 1) + NewLine);
lp.print_str("Notice that get_mat returns the value of the original unscaled problem" + NewLine);
lp.print_str("If there are any integer type variables, then only the rows are scaled" + NewLine);
lp.print_str("lp.set_int(3, false);" + NewLine);
lp.set_int(3, false);
lp.print_lp();
lp.solve();
lp.print_str("print_solution gives the solution to the original problem" + NewLine);
lp.print_objective();
lp.print_solution(1);
lp.print_constraints(1);
lp.print_str("Scaling is turned off with lp.unscale();" + NewLine);
lp.unscale();
lp.print_lp();
lp.print_str("Now turn B&B debugging off and simplex tracing on with" + NewLine);
lp.print_str("lp.set_debug(false); lp.set_trace(true); and lp.solve();" + NewLine);
lp.set_debug(false);
lp.set_trace(true);
lp.solve();
lp.print_str("Where possible, lp_solve will start at the last found basis" + NewLine);
lp.print_str("We can reset the problem to the initial basis with" + NewLine);
lp.print_str("default_basis lp. Now solve it again..." + NewLine);
lp.default_basis();
lp.solve();
lp.print_str("It is possible to give variables and constraints names" + NewLine);
lp.print_str("lp.set_row_name(1, \"speed\"); lp.set_col_name(2, \"money\");" + NewLine);
lp.set_row_name(1, "speed");
lp.set_col_name(2, "money");
lp.print_lp();
lp.print_str("As you can see, all column and rows are assigned default names" + NewLine);
lp.print_str("If a column or constraint is deleted, the names shift place also:" + NewLine);
lp.print_str("lp.del_column(1);" + NewLine);
lp.del_column(1);
lp.print_lp();
lp.write_lp("lp.lp");
lp.write_mps("lp.mps");
lp.set_outputfile(null);
}
using (var lp = LpSolve.read_LP("lp.lp", 0, "test"))
{
if (lp == null)
{
Console.Error.WriteLine("Can't find lp.lp, stopping");
return;
}
lp.set_outputfile("result2.txt");
lp.print_str("An lp structure can be created and read from a .lp file" + NewLine);
lp.print_str("lp = LpSolve.read_lp(\"lp.lp\", 0, \"test\");" + NewLine);
lp.print_str("The verbose option is disabled" + NewLine);
lp.print_str("lp is now:" + NewLine);
lp.print_lp();
lp.print_str("solution:" + NewLine);
lp.set_debug(true);
lpsolve_return statuscode = lp.solve();
string status = lp.get_statustext((int)statuscode);
Debug.WriteLine(status);
lp.set_debug(false);
lp.print_objective();
lp.print_solution(1);
lp.print_constraints(1);
lp.write_lp("lp.lp");
lp.write_mps("lp.mps");
lp.set_outputfile(null);
}
} //Test
private static int SolveA()
{
int lKolumn = 2; // trzy zmienne w modelu
using (LpSolve lp = LpSolve.make_lp(0, lKolumn))
{
if (lp == null)
{
return(1); // jesli nie moglo zbudowac modelu...
}
//nazwanie zmiennych
lp.set_col_name(1, "P1");
lp.set_col_name(2, "P2");
//przestrzen tablicowa do obliczen
int[] colno = new int[lKolumn];
double[] row = new double[lKolumn];
lp.set_add_rowmode(true);
int j = 0;
// rownanie pierwsze
j = 0;
colno[j] = 1;
row[j++] = 3;
colno[j] = 2;
row[j++] = 9;
// dodanie rzedu do lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 27) == false)
{
return(3);
}
// rownanie drugie
j = 0;
colno[j] = 1;
row[j++] = 8;
colno[j] = 2;
row[j++] = 4;
// dodanie rzedu do lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 32) == false)
{
return(3);
}
// rownanie trzecie
j = 0;
colno[j] = 1;
row[j++] = 12;
colno[j] = 2;
row[j++] = 3;
// dodanie rzedu do lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 36) == false)
{
return(3);
}
lp.set_add_rowmode(false);
//funkcja celu
j = 0;
colno[j] = 1;
row[j++] = 6;
colno[j] = 2;
row[j++] = 9;
if (lp.set_obj_fnex(j, row, colno) == false)
{
return(4);
}
// szukanie minimum
lp.set_minim();
lp.write_lp("model.lp");
lp.set_verbose(3);
lpsolve_return s = lp.solve();
if (s != lpsolve_return.OPTIMAL)
{
return(5);
}
Debug.WriteLine("Objective value: " + lp.get_objective());
lp.get_variables(row);
for (j = 0; j < lKolumn; j++)
{
Debug.WriteLine(lp.get_col_name(j + 1) + ": " + row[j]);
}
}
return(0);
}
private static int zadanie8()
{
int Ncol = 3; // trzy zmienne w modelu
using (LpSolve lp = LpSolve.make_lp(0, Ncol))
{
if (lp == null)
{
return(1); // jesli nie moglo zbudowac modelu...
}
//nazwanie zmiennych
lp.set_col_name(1, "W1");
lp.set_col_name(2, "W2");
lp.set_col_name(3, "W3");
//przestrzen tablicowa do obliczen
int[] colno = new int[Ncol];
double[] row = new double[Ncol];
lp.set_add_rowmode(true);
int j = 0;
/////////////////////////////////////// rownanie pierwsze
j = 0;
colno[j] = 1;
row[j++] = 1.5;
colno[j] = 2;
row[j++] = 3;
colno[j] = 3;
row[j++] = 4;
// dodanie rzedu do lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.LE, 1500) == false)
{
return(3);
}
/////////////////////////////////////////////////////////////////////// rownanie drugei
j = 0;
colno[j] = 1;
row[j++] = 3;
colno[j] = 2;
row[j++] = 2;
colno[j] = 3;
row[j++] = 1;
// dodanie rzedu do lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.LE, 1200) == false)
{
return(3);
}
lp.set_add_rowmode(false);
//funkcja celu
j = 0;
colno[j] = 1;
row[j++] = 12;
colno[j] = 2;
row[j++] = 18;
colno[j] = 3;
row[j++] = 12;
if (lp.set_obj_fnex(j, row, colno) == false)
{
return(4);
}
// szukanie maksa
lp.set_maxim();
lp.write_lp("model.lp");
lp.set_verbose(3);
lpsolve_return s = lp.solve();
if (s != lpsolve_return.OPTIMAL)
{
return(5);
}
Debug.WriteLine("Objective value: " + lp.get_objective());
lp.get_variables(row);
for (j = 0; j < Ncol; j++)
{
Debug.WriteLine(lp.get_col_name(j + 1) + ": " + row[j]);
}
}
return(0);
}
public int SolveLinearForCol()
{
int Ncol = _matrix.GetLength(1);//5 columns
int Nrow = _matrix.GetLength(0);
using (LpSolve lp = LpSolve.make_lp(Nrow, Ncol))
{
if (lp == null)
{
return(1); // couldn't construct a new model...
}
lp.set_col_name(1, "x1");
lp.set_col_name(2, "x2");
lp.set_col_name(3, "x3");
lp.set_col_name(4, "x4");
lp.set_col_name(5, "x5");
//create space large enough for one row
int[] colno = new int[Ncol];
double[] row = new double[Ncol];
// makes building the model faster if it is done rows by row
lp.set_add_rowmode(true);
// 4 10 16 14 17
// 5 4 2 16 14
// 17 3 6 10 15
// 14 16 18 4 7
// 6 3 10 18 15
//construct first row (4x1 + 5x2 +176x3 + 14x4 + 6x5 <= -1)
int j = 0;
colno[j] = 1; // first column
row[j++] = 4;
colno[j] = 2; // second column
row[j++] = 5;
colno[j] = 3; // second column
row[j++] = 17;
colno[j] = 4; // second column
row[j++] = 14;
colno[j] = 5; // second column
row[j++] = 6;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 1) == false)
{
return(3);
}
//construct 2 row (10x1 + 4x2 +3x3 + 16x4 + 3x5 <= -1)
j = 0;
colno[j] = 1; // first column
row[j++] = 10;
colno[j] = 2; // second column
row[j++] = 4;
colno[j] = 3; // second column
row[j++] = 3;
colno[j] = 4; // second column
row[j++] = 16;
colno[j] = 5; // second column
row[j++] = 3;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 1) == false)
{
return(3);
}
//construct 3 row (16x1 + 2x2 +6x3 + 18x4 + 10x5 <= -1)
j = 0;
colno[j] = 1; // first column
row[j++] = 16;
colno[j] = 2; // second column
row[j++] = 2;
colno[j] = 3; // second column
row[j++] = 6;
colno[j] = 4; // second column
row[j++] = 18;
colno[j] = 5; // second column
row[j++] = 10;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 1) == false)
{
return(3);
}
//construct 4 row (14x1 + 16x2 +10x3 + 4x4 + 18x5 <= -1)
j = 0;
colno[j] = 1; // first column
row[j++] = 14;
colno[j] = 2; // second column
row[j++] = 16;
colno[j] = 3; // second column
row[j++] = 10;
colno[j] = 4; // second column
row[j++] = 4;
colno[j] = 5; // second column
row[j++] = 18;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 1) == false)
{
return(3);
}
//construct 5 row (17x1 + 14x2 +15x3 + 7x4 + 15x5 <= -1)
j = 0;
colno[j] = 1; // first column
row[j++] = 17;
colno[j] = 2; // second column
row[j++] = 14;
colno[j] = 3; // second column
row[j++] = 15;
colno[j] = 4; // second column
row[j++] = 7;
colno[j] = 5; // second column
row[j++] = 15;
// add the row to lpsolve
if (lp.add_constraintex(j, row, colno, lpsolve_constr_types.GE, 1) == false)
{
return(3);
}
lp.set_add_rowmode(false);
//set the objective function (1 x + 1 x2 +x3+x4+x5)
j = 0;
colno[j] = 1; // first column
row[j++] = 1;
colno[j] = 2; // second column
row[j++] = 1;
colno[j] = 3; // 3 column
row[j++] = 1;
colno[j] = 4; // 4 column
row[j++] = 1;
colno[j] = 5; // 5 column
row[j++] = 1;
if (lp.set_obj_fnex(j, row, colno) == false)
{
return(4);
}
// set the object direction to maximize
lp.set_minim();
// just out of curioucity, now show the model in lp format on screen
// this only works if this is a console application. If not, use write_lp and a filename
lp.write_lp("model2.lp");
// I only want to see important messages on screen while solving
lp.set_verbose(lpsolve_verbosity.IMPORTANT);
// Now let lpsolve calculate a solution
lpsolve_return s = lp.solve();
if (s != lpsolve_return.OPTIMAL)
{
return(5);
}
// a solution is calculated, now lets get some results
// objective value
Debug.WriteLine("Objective value: " + lp.get_objective());
// variable values
lp.get_variables(row);
for (j = 0; j < Ncol; j++)
{
Console.WriteLine(lp.get_col_name(j + 1) + ": " + row[j]);
}
}
return(1);
}
