Better doc.
2 * lemon/lp_base.h - Part of LEMON, a generic C++ optimization library
4 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Research Group on Combinatorial Optimization, EGRES).
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
17 #ifndef LEMON_LP_BASE_H
18 #define LEMON_LP_BASE_H
25 #include<lemon/utility.h>
26 #include<lemon/error.h>
27 #include<lemon/invalid.h>
30 ///\brief The interface of the LP solver interface.
31 ///\ingroup gen_opt_group
34 ///Internal data structure to convert floating id's to fix one's
36 ///\todo This might be implemented to be also usable in other places.
40 std::vector<int> index;
41 std::vector<int> cross;
44 _FixId() : first_free(-1) {};
45 ///Convert a floating id to a fix one
47 ///\param n is a floating id
48 ///\return the corresponding fix id
49 int fixId(int n) const {return cross[n];}
50 ///Convert a fix id to a floating one
52 ///\param n is a fix id
53 ///\return the corresponding floating id
54 int floatingId(int n) const { return index[n];}
55 ///Add a new floating id.
57 ///\param n is a floating id
58 ///\return the fix id of the new value
59 ///\todo Multiple additions should also be handled.
62 if(n>=int(cross.size())) {
65 cross[n]=index.size();
70 int next=index[first_free];
76 ///\todo Create an own exception type.
77 else throw LogicError(); //floatingId-s must form a continuous range;
81 ///\param n is a fix id
88 for(int i=fl+1;i<int(cross.size());++i) {
94 ///An upper bound on the largest fix id.
96 ///\todo Do we need this?
98 std::size_t maxFixId() { return cross.size()-1; }
102 ///Common base class for LP solvers
104 ///\todo Much more docs
105 ///\ingroup gen_opt_group
110 ///Possible outcomes of an LP solving procedure
111 enum SolveExitStatus {
112 ///This means that the problem has been successfully solved: either
113 ///an optimal solution has been found or infeasibility/unboundedness
116 ///Any other case (including the case when some user specified limit has been exceeded)
121 enum SolutionStatus {
122 ///Feasible solution has'n been found (but may exist).
124 ///\todo NOTFOUND might be a better name.
127 ///The problem has no feasible solution
129 ///Feasible solution found
131 ///Optimal solution exists and found
133 ///The cost function is unbounded
135 ///\todo Give a feasible solution and an infinite ray (and the
136 ///corresponding bases)
140 ///\e The type of the investigated LP problem
142 ///Primal-dual feasible
143 PRIMAL_DUAL_FEASIBLE = 0,
144 ///Primal feasible dual infeasible
145 PRIMAL_FEASIBLE_DUAL_INFEASIBLE = 1,
146 ///Primal infeasible dual feasible
147 PRIMAL_INFEASIBLE_DUAL_FEASIBLE = 2,
148 ///Primal-dual infeasible
149 PRIMAL_DUAL_INFEASIBLE = 3,
150 ///Could not determine so far
154 ///The floating point type used by the solver
155 typedef double Value;
156 ///The infinity constant
157 static const Value INF;
158 ///The not a number constant
159 static const Value NaN;
161 ///Refer to a column of the LP.
163 ///This type is used to refer to a column of the LP.
165 ///Its value remains valid and correct even after the addition or erase of
168 ///\todo Document what can one do with a Col (INVALID, comparing,
169 ///it is similar to Node/Edge)
173 friend class LpSolverBase;
175 typedef Value ExprValue;
176 typedef True LpSolverCol;
178 Col(const Invalid&) : id(-1) {}
179 bool operator<(Col c) const {return id<c.id;}
180 bool operator==(Col c) const {return id==c.id;}
181 bool operator!=(Col c) const {return id==c.id;}
184 ///Refer to a row of the LP.
186 ///This type is used to refer to a row of the LP.
188 ///Its value remains valid and correct even after the addition or erase of
191 ///\todo Document what can one do with a Row (INVALID, comparing,
192 ///it is similar to Node/Edge)
196 friend class LpSolverBase;
198 typedef Value ExprValue;
199 typedef True LpSolverRow;
201 Row(const Invalid&) : id(-1) {}
203 bool operator<(Row c) const {return id<c.id;}
204 bool operator==(Row c) const {return id==c.id;}
205 bool operator!=(Row c) const {return id==c.id;}
208 ///Linear expression of variables and a constant component
210 ///This data structure strores a linear expression of the variables
211 ///(\ref Col "Col"s) and also has a constant component.
213 ///There are several ways to access and modify the contents of this
215 ///- Its it fully compatible with \c std::map<Col,double>, so for expamle
216 ///if \c e is an Expr and \c v and \c w are of type \ref Col, then you can
217 ///read and modify the coefficients like
224 ///or you can also iterate through its elements.
227 ///for(LpSolverBase::Expr::iterator i=e.begin();i!=e.end();++i)
230 ///(This code computes the sum of all coefficients).
231 ///- Numbers (<tt>double</tt>'s)
232 ///and variables (\ref Col "Col"s) directly convert to an
233 ///\ref Expr and the usual linear operations are defined so
236 ///2*v-3.12*(v-w/2)+2
237 ///v*2.1+(3*v+(v*12+w+6)*3)/2
239 ///are valid \ref Expr "Expr"essions.
240 ///The usual assignment operations are also defined.
243 ///e+=2*v-3.12*(v-w/2)+2;
247 ///- The constant member can be set and read by \ref constComp()
250 ///double c=e.constComp();
253 ///\note \ref clear() not only sets all coefficients to 0 but also
254 ///clears the constant components.
258 class Expr : public std::map<Col,Value>
261 typedef LpSolverBase::Col Key;
262 typedef LpSolverBase::Value Value;
265 typedef std::map<Col,Value> Base;
269 typedef True IsLinExpression;
271 Expr() : Base(), const_comp(0) { }
273 Expr(const Key &v) : const_comp(0) {
274 Base::insert(std::make_pair(v, 1));
277 Expr(const Value &v) : const_comp(v) {}
279 void set(const Key &v,const Value &c) {
280 Base::insert(std::make_pair(v, c));
283 Value &constComp() { return const_comp; }
285 const Value &constComp() const { return const_comp; }
287 ///Removes the components with zero coefficient.
289 for (Base::iterator i=Base::begin(); i!=Base::end();) {
292 if ((*i).second==0) Base::erase(i);
297 ///Removes the coefficients closer to zero than \c tolerance.
298 void simplify(double &tolerance) {
299 for (Base::iterator i=Base::begin(); i!=Base::end();) {
302 if (std::fabs((*i).second)<tolerance) Base::erase(i);
307 ///Sets all coefficients and the constant component to 0.
314 Expr &operator+=(const Expr &e) {
315 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
316 (*this)[j->first]+=j->second;
317 const_comp+=e.const_comp;
321 Expr &operator-=(const Expr &e) {
322 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
323 (*this)[j->first]-=j->second;
324 const_comp-=e.const_comp;
328 Expr &operator*=(const Value &c) {
329 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
335 Expr &operator/=(const Value &c) {
336 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
345 ///This data stucture represents a linear constraint in the LP.
346 ///Basically it is a linear expression with a lower or an upper bound
347 ///(or both). These parts of the constraint can be obtained by the member
348 ///functions \ref expr(), \ref lowerBound() and \ref upperBound(),
350 ///There are two ways to construct a constraint.
351 ///- You can set the linear expression and the bounds directly
352 /// by the functions above.
353 ///- The operators <tt>\<=</tt>, <tt>==</tt> and <tt>\>=</tt>
354 /// are defined between expressions, or even between constraints whenever
355 /// it makes sense. Therefore if \c e and \c f are linear expressions and
356 /// \c s and \c t are numbers, then the followings are valid expressions
357 /// and thus they can be used directly e.g. in \ref addRow() whenever
365 ///\warning The validity of a constraint is checked only at run time, so
366 ///e.g. \ref addRow(<tt>x[1]\<=x[2]<=5</tt>) will compile, but will throw a
367 ///\ref LogicError exception.
371 typedef LpSolverBase::Expr Expr;
372 typedef Expr::Key Key;
373 typedef Expr::Value Value;
375 // static const Value INF;
376 // static const Value NaN;
383 Constr() : _expr(), _lb(NaN), _ub(NaN) {}
385 Constr(Value lb,const Expr &e,Value ub) :
386 _expr(e), _lb(lb), _ub(ub) {}
388 Constr(const Expr &e,Value ub) :
389 _expr(e), _lb(NaN), _ub(ub) {}
391 Constr(Value lb,const Expr &e) :
392 _expr(e), _lb(lb), _ub(NaN) {}
394 Constr(const Expr &e) :
395 _expr(e), _lb(NaN), _ub(NaN) {}
403 ///Reference to the linear expression
404 Expr &expr() { return _expr; }
405 ///Cont reference to the linear expression
406 const Expr &expr() const { return _expr; }
407 ///Reference to the lower bound.
410 ///- \ref INF "INF": the constraint is lower unbounded.
411 ///- \ref NaN "NaN": lower bound has not been set.
412 ///- finite number: the lower bound
413 Value &lowerBound() { return _lb; }
414 ///The const version of \ref lowerBound()
415 const Value &lowerBound() const { return _lb; }
416 ///Reference to the upper bound.
419 ///- \ref INF "INF": the constraint is upper unbounded.
420 ///- \ref NaN "NaN": upper bound has not been set.
421 ///- finite number: the upper bound
422 Value &upperBound() { return _ub; }
423 ///The const version of \ref upperBound()
424 const Value &upperBound() const { return _ub; }
425 ///Is the constraint lower bounded?
426 bool lowerBounded() const {
430 ///Is the constraint upper bounded?
431 bool upperBounded() const {
437 ///Linear expression of rows
439 ///This data structure represents a column of the matrix,
440 ///thas is it strores a linear expression of the dual variables
441 ///(\ref Row "Row"s).
443 ///There are several ways to access and modify the contents of this
445 ///- Its it fully compatible with \c std::map<Row,double>, so for expamle
446 ///if \c e is an DualExpr and \c v
447 ///and \c w are of type \ref Row, then you can
448 ///read and modify the coefficients like
455 ///or you can also iterate through its elements.
458 ///for(LpSolverBase::DualExpr::iterator i=e.begin();i!=e.end();++i)
461 ///(This code computes the sum of all coefficients).
462 ///- Numbers (<tt>double</tt>'s)
463 ///and variables (\ref Row "Row"s) directly convert to an
464 ///\ref DualExpr and the usual linear operations are defined so
468 ///v*2.1+(3*v+(v*12+w)*3)/2
470 ///are valid \ref DualExpr "DualExpr"essions.
471 ///The usual assignment operations are also defined.
474 ///e+=2*v-3.12*(v-w/2);
481 class DualExpr : public std::map<Row,Value>
484 typedef LpSolverBase::Row Key;
485 typedef LpSolverBase::Value Value;
488 typedef std::map<Row,Value> Base;
491 typedef True IsLinExpression;
493 DualExpr() : Base() { }
495 DualExpr(const Key &v) {
496 Base::insert(std::make_pair(v, 1));
499 void set(const Key &v,const Value &c) {
500 Base::insert(std::make_pair(v, c));
503 ///Removes the components with zero coefficient.
505 for (Base::iterator i=Base::begin(); i!=Base::end();) {
508 if ((*i).second==0) Base::erase(i);
513 ///Removes the coefficients closer to zero than \c tolerance.
514 void simplify(double &tolerance) {
515 for (Base::iterator i=Base::begin(); i!=Base::end();) {
518 if (std::fabs((*i).second)<tolerance) Base::erase(i);
524 ///Sets all coefficients to 0.
530 DualExpr &operator+=(const DualExpr &e) {
531 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
532 (*this)[j->first]+=j->second;
536 DualExpr &operator-=(const DualExpr &e) {
537 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
538 (*this)[j->first]-=j->second;
542 DualExpr &operator*=(const Value &c) {
543 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
548 DualExpr &operator/=(const Value &c) {
549 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
560 //Abstract virtual functions
561 virtual LpSolverBase &_newLp() = 0;
562 virtual LpSolverBase &_copyLp(){
563 ///\todo This should be implemented here, too, when we have problem retrieving routines. It can be overriden.
566 LpSolverBase & newlp(_newLp());
568 //return *(LpSolverBase*)0;
571 virtual int _addCol() = 0;
572 virtual int _addRow() = 0;
573 virtual void _eraseCol(int col) = 0;
574 virtual void _eraseRow(int row) = 0;
575 virtual void _setRowCoeffs(int i,
578 Value const * values ) = 0;
579 virtual void _setColCoeffs(int i,
582 Value const * values ) = 0;
583 virtual void _setCoeff(int row, int col, Value value) = 0;
584 virtual void _setColLowerBound(int i, Value value) = 0;
585 virtual void _setColUpperBound(int i, Value value) = 0;
586 // virtual void _setRowLowerBound(int i, Value value) = 0;
587 // virtual void _setRowUpperBound(int i, Value value) = 0;
588 virtual void _setRowBounds(int i, Value lower, Value upper) = 0;
589 virtual void _setObjCoeff(int i, Value obj_coef) = 0;
590 virtual void _clearObj()=0;
591 // virtual void _setObj(int length,
592 // int const * indices,
593 // Value const * values ) = 0;
594 virtual SolveExitStatus _solve() = 0;
595 virtual Value _getPrimal(int i) = 0;
596 virtual Value _getDual(int i) = 0;
597 virtual Value _getPrimalValue() = 0;
598 virtual SolutionStatus _getPrimalStatus() = 0;
599 virtual SolutionStatus _getDualStatus() = 0;
600 ///\todo This could be implemented here, too, using _getPrimalStatus() and
602 virtual ProblemTypes _getProblemType() = 0;
604 virtual void _setMax() = 0;
605 virtual void _setMin() = 0;
607 //Own protected stuff
609 //Constant component of the objective function
610 Value obj_const_comp;
618 LpSolverBase() : obj_const_comp(0) {}
621 virtual ~LpSolverBase() {}
623 ///Creates a new LP problem
624 LpSolverBase &newLp() {return _newLp();}
625 ///Makes a copy of the LP problem
626 LpSolverBase ©Lp() {return _copyLp();}
628 ///\name Build up and modify the LP
632 ///Add a new empty column (i.e a new variable) to the LP
633 Col addCol() { Col c; c.id=cols.insert(_addCol()); return c;}
635 ///\brief Adds several new columns
636 ///(i.e a variables) at once
638 ///This magic function takes a container as its argument
639 ///and fills its elements
640 ///with new columns (i.e. variables)
642 ///- a standard STL compatible iterable container with
643 ///\ref Col as its \c values_type
646 ///std::vector<LpSolverBase::Col>
647 ///std::list<LpSolverBase::Col>
649 ///- a standard STL compatible iterable container with
650 ///\ref Col as its \c mapped_type
653 ///std::map<AnyType,LpSolverBase::Col>
655 ///- an iterable lemon \ref concept::WriteMap "write map" like
657 ///ListGraph::NodeMap<LpSolverBase::Col>
658 ///ListGraph::EdgeMap<LpSolverBase::Col>
660 ///\return The number of the created column.
663 int addColSet(T &t) { return 0;}
666 typename enable_if<typename T::value_type::LpSolverCol,int>::type
667 addColSet(T &t,dummy<0> = 0) {
669 for(typename T::iterator i=t.begin();i!=t.end();++i) {*i=addCol();s++;}
673 typename enable_if<typename T::value_type::second_type::LpSolverCol,
675 addColSet(T &t,dummy<1> = 1) {
677 for(typename T::iterator i=t.begin();i!=t.end();++i) {
684 typename enable_if<typename T::ValueSet::value_type::LpSolverCol,
686 addColSet(T &t,dummy<2> = 2) {
687 ///\bug <tt>return addColSet(t.valueSet());</tt> should also work.
689 for(typename T::ValueSet::iterator i=t.valueSet().begin();
690 i!=t.valueSet().end();
700 ///Set a column (i.e a dual constraint) of the LP
702 ///\param c is the column to be modified
703 ///\param e is a dual linear expression (see \ref DualExpr)
704 ///\bug This is a temporary function. The interface will change to
706 void setCol(Col c,const DualExpr &e) {
707 std::vector<int> indices;
708 std::vector<Value> values;
709 indices.push_back(0);
711 for(DualExpr::const_iterator i=e.begin(); i!=e.end(); ++i)
712 if((*i).second!=0) { ///\bug EPSILON would be necessary here!!!
713 indices.push_back(rows.floatingId((*i).first.id));
714 values.push_back((*i).second);
716 _setColCoeffs(cols.floatingId(c.id),indices.size()-1,
717 &indices[0],&values[0]);
720 ///Add a new column to the LP
722 ///\param e is a dual linear expression (see \ref DualExpr)
723 ///\param obj is the corresponding component of the objective
724 ///function. It is 0 by default.
725 ///\return The created column.
726 ///\bug This is a temportary function. The interface will change to
728 Col addCol(const DualExpr &e, Value obj=0) {
735 ///Add a new empty row (i.e a new constraint) to the LP
737 ///This function adds a new empty row (i.e a new constraint) to the LP.
738 ///\return The created row
739 Row addRow() { Row r; r.id=rows.insert(_addRow()); return r;}
741 ///\brief Add several new rows
742 ///(i.e a constraints) at once
744 ///This magic function takes a container as its argument
745 ///and fills its elements
746 ///with new row (i.e. variables)
748 ///- a standard STL compatible iterable container with
749 ///\ref Row as its \c values_type
752 ///std::vector<LpSolverBase::Row>
753 ///std::list<LpSolverBase::Row>
755 ///- a standard STL compatible iterable container with
756 ///\ref Row as its \c mapped_type
759 ///std::map<AnyType,LpSolverBase::Row>
761 ///- an iterable lemon \ref concept::WriteMap "write map" like
763 ///ListGraph::NodeMap<LpSolverBase::Row>
764 ///ListGraph::EdgeMap<LpSolverBase::Row>
766 ///\return The number of rows created.
769 int addRowSet(T &t) { return 0;}
772 typename enable_if<typename T::value_type::LpSolverRow,int>::type
773 addRowSet(T &t,dummy<0> = 0) {
775 for(typename T::iterator i=t.begin();i!=t.end();++i) {*i=addRow();s++;}
779 typename enable_if<typename T::value_type::second_type::LpSolverRow,
781 addRowSet(T &t,dummy<1> = 1) {
783 for(typename T::iterator i=t.begin();i!=t.end();++i) {
790 typename enable_if<typename T::ValueSet::value_type::LpSolverRow,
792 addRowSet(T &t,dummy<2> = 2) {
793 ///\bug <tt>return addRowSet(t.valueSet());</tt> should also work.
795 for(typename T::ValueSet::iterator i=t.valueSet().begin();
796 i!=t.valueSet().end();
806 ///Set a row (i.e a constraint) of the LP
808 ///\param r is the row to be modified
809 ///\param l is lower bound (-\ref INF means no bound)
810 ///\param e is a linear expression (see \ref Expr)
811 ///\param u is the upper bound (\ref INF means no bound)
812 ///\bug This is a temportary function. The interface will change to
814 ///\todo Option to control whether a constraint with a single variable is
816 void setRow(Row r, Value l,const Expr &e, Value u) {
817 std::vector<int> indices;
818 std::vector<Value> values;
819 indices.push_back(0);
821 for(Expr::const_iterator i=e.begin(); i!=e.end(); ++i)
822 if((*i).second!=0) { ///\bug EPSILON would be necessary here!!!
823 indices.push_back(cols.floatingId((*i).first.id));
824 values.push_back((*i).second);
826 _setRowCoeffs(rows.floatingId(r.id),indices.size()-1,
827 &indices[0],&values[0]);
828 // _setRowLowerBound(rows.floatingId(r.id),l-e.constComp());
829 // _setRowUpperBound(rows.floatingId(r.id),u-e.constComp());
830 _setRowBounds(rows.floatingId(r.id),l-e.constComp(),u-e.constComp());
833 ///Set a row (i.e a constraint) of the LP
835 ///\param r is the row to be modified
836 ///\param c is a linear expression (see \ref Constr)
837 void setRow(Row r, const Constr &c) {
839 c.lowerBounded()?c.lowerBound():-INF,
841 c.upperBounded()?c.upperBound():INF);
844 ///Add a new row (i.e a new constraint) to the LP
846 ///\param l is the lower bound (-\ref INF means no bound)
847 ///\param e is a linear expression (see \ref Expr)
848 ///\param u is the upper bound (\ref INF means no bound)
849 ///\return The created row.
850 ///\bug This is a temportary function. The interface will change to
852 Row addRow(Value l,const Expr &e, Value u) {
858 ///Add a new row (i.e a new constraint) to the LP
860 ///\param c is a linear expression (see \ref Constr)
861 ///\return The created row.
862 Row addRow(const Constr &c) {
867 ///Erase a coloumn (i.e a variable) from the LP
869 ///\param c is the coloumn to be deleted
870 ///\todo Please check this
871 void eraseCol(Col c) {
872 _eraseCol(cols.floatingId(c.id));
875 ///Erase a row (i.e a constraint) from the LP
877 ///\param r is the row to be deleted
878 ///\todo Please check this
879 void eraseRow(Row r) {
880 _eraseRow(rows.floatingId(r.id));
884 ///Set an element of the coefficient matrix of the LP
886 ///\param r is the row of the element to be modified
887 ///\param c is the coloumn of the element to be modified
888 ///\param val is the new value of the coefficient
889 void setCoeff(Row r, Col c, Value val){
890 _setCoeff(rows.floatingId(r.id),cols.floatingId(c.id), val);
893 /// Set the lower bound of a column (i.e a variable)
895 /// The upper bound of a variable (column) has to be given by an
896 /// extended number of type Value, i.e. a finite number of type
897 /// Value or -\ref INF.
898 void colLowerBound(Col c, Value value) {
899 _setColLowerBound(cols.floatingId(c.id),value);
901 /// Set the upper bound of a column (i.e a variable)
903 /// The upper bound of a variable (column) has to be given by an
904 /// extended number of type Value, i.e. a finite number of type
905 /// Value or \ref INF.
906 void colUpperBound(Col c, Value value) {
907 _setColUpperBound(cols.floatingId(c.id),value);
909 /// Set the lower and the upper bounds of a column (i.e a variable)
911 /// The lower and the upper bounds of
912 /// a variable (column) have to be given by an
913 /// extended number of type Value, i.e. a finite number of type
914 /// Value, -\ref INF or \ref INF.
915 void colBounds(Col c, Value lower, Value upper) {
916 _setColLowerBound(cols.floatingId(c.id),lower);
917 _setColUpperBound(cols.floatingId(c.id),upper);
920 // /// Set the lower bound of a row (i.e a constraint)
922 // /// The lower bound of a linear expression (row) has to be given by an
923 // /// extended number of type Value, i.e. a finite number of type
924 // /// Value or -\ref INF.
925 // void rowLowerBound(Row r, Value value) {
926 // _setRowLowerBound(rows.floatingId(r.id),value);
928 // /// Set the upper bound of a row (i.e a constraint)
930 // /// The upper bound of a linear expression (row) has to be given by an
931 // /// extended number of type Value, i.e. a finite number of type
932 // /// Value or \ref INF.
933 // void rowUpperBound(Row r, Value value) {
934 // _setRowUpperBound(rows.floatingId(r.id),value);
937 /// Set the lower and the upper bounds of a row (i.e a constraint)
939 /// The lower and the upper bounds of
940 /// a constraint (row) have to be given by an
941 /// extended number of type Value, i.e. a finite number of type
942 /// Value, -\ref INF or \ref INF.
943 void rowBounds(Row c, Value lower, Value upper) {
944 _setRowBounds(rows.floatingId(c.id),lower, upper);
945 // _setRowUpperBound(rows.floatingId(c.id),upper);
948 ///Set an element of the objective function
949 void objCoeff(Col c, Value v) {_setObjCoeff(cols.floatingId(c.id),v); };
950 ///Set the objective function
952 ///\param e is a linear expression of type \ref Expr.
953 ///\bug The previous objective function is not cleared!
954 void setObj(Expr e) {
956 for (Expr::iterator i=e.begin(); i!=e.end(); ++i)
957 objCoeff((*i).first,(*i).second);
958 obj_const_comp=e.constComp();
962 void max() { _setMax(); }
964 void min() { _setMin(); }
970 ///\name Solve the LP
974 ///\e Solve the LP problem at hand
976 ///\return The result of the optimization procedure. Possible values and their meanings can be found in the documentation of \ref SolveExitStatus.
978 ///\todo Which method is used to solve the problem
979 SolveExitStatus solve() { return _solve(); }
983 ///\name Obtain the solution
987 /// The status of the primal problem (the original LP problem)
988 SolutionStatus primalStatus() {
989 return _getPrimalStatus();
992 /// The status of the dual (of the original LP) problem
993 SolutionStatus dualStatus() {
994 return _getDualStatus();
997 ///The type of the original LP problem
998 ProblemTypes problemType() {
999 return _getProblemType();
1003 Value primal(Col c) { return _getPrimal(cols.floatingId(c.id)); }
1006 Value dual(Row r) { return _getDual(rows.floatingId(r.id)); }
1011 ///- \ref INF or -\ref INF means either infeasibility or unboundedness
1012 /// of the primal problem, depending on whether we minimize or maximize.
1013 ///- \ref NaN if no primal solution is found.
1014 ///- The (finite) objective value if an optimal solution is found.
1015 Value primalValue() { return _getPrimalValue()+obj_const_comp;}
1022 ///\relates LpSolverBase::Expr
1024 inline LpSolverBase::Expr operator+(const LpSolverBase::Expr &a,
1025 const LpSolverBase::Expr &b)
1027 LpSolverBase::Expr tmp(a);
1033 ///\relates LpSolverBase::Expr
1035 inline LpSolverBase::Expr operator-(const LpSolverBase::Expr &a,
1036 const LpSolverBase::Expr &b)
1038 LpSolverBase::Expr tmp(a);
1044 ///\relates LpSolverBase::Expr
1046 inline LpSolverBase::Expr operator*(const LpSolverBase::Expr &a,
1047 const LpSolverBase::Value &b)
1049 LpSolverBase::Expr tmp(a);
1056 ///\relates LpSolverBase::Expr
1058 inline LpSolverBase::Expr operator*(const LpSolverBase::Value &a,
1059 const LpSolverBase::Expr &b)
1061 LpSolverBase::Expr tmp(b);
1067 ///\relates LpSolverBase::Expr
1069 inline LpSolverBase::Expr operator/(const LpSolverBase::Expr &a,
1070 const LpSolverBase::Value &b)
1072 LpSolverBase::Expr tmp(a);
1079 ///\relates LpSolverBase::Constr
1081 inline LpSolverBase::Constr operator<=(const LpSolverBase::Expr &e,
1082 const LpSolverBase::Expr &f)
1084 return LpSolverBase::Constr(-LpSolverBase::INF,e-f,0);
1089 ///\relates LpSolverBase::Constr
1091 inline LpSolverBase::Constr operator<=(const LpSolverBase::Value &e,
1092 const LpSolverBase::Expr &f)
1094 return LpSolverBase::Constr(e,f);
1099 ///\relates LpSolverBase::Constr
1101 inline LpSolverBase::Constr operator<=(const LpSolverBase::Expr &e,
1102 const LpSolverBase::Value &f)
1104 return LpSolverBase::Constr(e,f);
1109 ///\relates LpSolverBase::Constr
1111 inline LpSolverBase::Constr operator>=(const LpSolverBase::Expr &e,
1112 const LpSolverBase::Expr &f)
1114 return LpSolverBase::Constr(-LpSolverBase::INF,f-e,0);
1120 ///\relates LpSolverBase::Constr
1122 inline LpSolverBase::Constr operator>=(const LpSolverBase::Value &e,
1123 const LpSolverBase::Expr &f)
1125 return LpSolverBase::Constr(f,e);
1131 ///\relates LpSolverBase::Constr
1133 inline LpSolverBase::Constr operator>=(const LpSolverBase::Expr &e,
1134 const LpSolverBase::Value &f)
1136 return LpSolverBase::Constr(f,e);
1141 ///\relates LpSolverBase::Constr
1143 inline LpSolverBase::Constr operator==(const LpSolverBase::Expr &e,
1144 const LpSolverBase::Expr &f)
1146 return LpSolverBase::Constr(0,e-f,0);
1151 ///\relates LpSolverBase::Constr
1153 inline LpSolverBase::Constr operator<=(const LpSolverBase::Value &n,
1154 const LpSolverBase::Constr&c)
1156 LpSolverBase::Constr tmp(c);
1157 ///\todo Create an own exception type.
1158 if(!isnan(tmp.lowerBound())) throw LogicError();
1159 else tmp.lowerBound()=n;
1164 ///\relates LpSolverBase::Constr
1166 inline LpSolverBase::Constr operator<=(const LpSolverBase::Constr& c,
1167 const LpSolverBase::Value &n)
1169 LpSolverBase::Constr tmp(c);
1170 ///\todo Create an own exception type.
1171 if(!isnan(tmp.upperBound())) throw LogicError();
1172 else tmp.upperBound()=n;
1178 ///\relates LpSolverBase::Constr
1180 inline LpSolverBase::Constr operator>=(const LpSolverBase::Value &n,
1181 const LpSolverBase::Constr&c)
1183 LpSolverBase::Constr tmp(c);
1184 ///\todo Create an own exception type.
1185 if(!isnan(tmp.upperBound())) throw LogicError();
1186 else tmp.upperBound()=n;
1191 ///\relates LpSolverBase::Constr
1193 inline LpSolverBase::Constr operator>=(const LpSolverBase::Constr& c,
1194 const LpSolverBase::Value &n)
1196 LpSolverBase::Constr tmp(c);
1197 ///\todo Create an own exception type.
1198 if(!isnan(tmp.lowerBound())) throw LogicError();
1199 else tmp.lowerBound()=n;
1205 ///\relates LpSolverBase::DualExpr
1207 inline LpSolverBase::DualExpr operator+(const LpSolverBase::DualExpr &a,
1208 const LpSolverBase::DualExpr &b)
1210 LpSolverBase::DualExpr tmp(a);
1216 ///\relates LpSolverBase::DualExpr
1218 inline LpSolverBase::DualExpr operator-(const LpSolverBase::DualExpr &a,
1219 const LpSolverBase::DualExpr &b)
1221 LpSolverBase::DualExpr tmp(a);
1227 ///\relates LpSolverBase::DualExpr
1229 inline LpSolverBase::DualExpr operator*(const LpSolverBase::DualExpr &a,
1230 const LpSolverBase::Value &b)
1232 LpSolverBase::DualExpr tmp(a);
1239 ///\relates LpSolverBase::DualExpr
1241 inline LpSolverBase::DualExpr operator*(const LpSolverBase::Value &a,
1242 const LpSolverBase::DualExpr &b)
1244 LpSolverBase::DualExpr tmp(b);
1250 ///\relates LpSolverBase::DualExpr
1252 inline LpSolverBase::DualExpr operator/(const LpSolverBase::DualExpr &a,
1253 const LpSolverBase::Value &b)
1255 LpSolverBase::DualExpr tmp(a);
1263 #endif //LEMON_LP_BASE_H