Added copyright header and description.
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.
39 std::vector<int> index;
40 std::vector<int> cross;
43 _FixId() : first_free(-1) {};
44 ///Convert a floating id to a fix one
46 ///\param n is a floating id
47 ///\return the corresponding fix id
48 int fixId(int n) const {return cross[n];}
49 ///Convert a fix id to a floating one
51 ///\param n is a fix id
52 ///\return the corresponding floating id
53 int floatingId(int n) const { return index[n];}
54 ///Add a new floating id.
56 ///\param n is a floating id
57 ///\return the fix id of the new value
58 ///\todo Multiple additions should also be handled.
61 if(n>=int(cross.size())) {
64 cross[n]=index.size();
69 int next=index[first_free];
75 ///\todo Create an own exception type.
76 else throw LogicError(); //floatingId-s must form a continuous range;
80 ///\param n is a fix id
87 for(int i=fl+1;i<int(cross.size());++i) {
93 ///An upper bound on the largest fix id.
95 ///\todo Do we need this?
97 std::size_t maxFixId() { return cross.size()-1; }
101 ///Common base class for LP solvers
103 ///\todo Much more docs
104 ///\ingroup gen_opt_group
109 ///Possible outcomes of an LP solving procedure
110 enum SolveExitStatus {
111 ///This means that the problem has been successfully solved: either
112 ///an optimal solution has been found or infeasibility/unboundedness
115 ///Any other case (including the case when some user specified limit has been exceeded)
120 enum SolutionStatus {
121 ///Feasible solution has'n been found (but may exist).
123 ///\todo NOTFOUND might be a better name.
126 ///The problem has no feasible solution
128 ///Feasible solution found
130 ///Optimal solution exists and found
132 ///The cost function is unbounded
134 ///\todo Give a feasible solution and an infinite ray (and the
135 ///corresponding bases)
139 ///\e The type of the investigated LP problem
141 ///Primal-dual feasible
142 PRIMAL_DUAL_FEASIBLE = 0,
143 ///Primal feasible dual infeasible
144 PRIMAL_FEASIBLE_DUAL_INFEASIBLE = 1,
145 ///Primal infeasible dual feasible
146 PRIMAL_INFEASIBLE_DUAL_FEASIBLE = 2,
147 ///Primal-dual infeasible
148 PRIMAL_DUAL_INFEASIBLE = 3,
149 ///Could not determine so far
153 ///The floating point type used by the solver
154 typedef double Value;
155 ///The infinity constant
156 static const Value INF;
157 ///The not a number constant
158 static const Value NaN;
160 ///Refer to a column of the LP.
162 ///This type is used to refer to a column of the LP.
164 ///Its value remains valid and correct even after the addition or erase of
167 ///\todo Document what can one do with a Col (INVALID, comparing,
168 ///it is similar to Node/Edge)
172 friend class LpSolverBase;
174 typedef Value ExprValue;
175 typedef True LpSolverCol;
177 Col(const Invalid&) : id(-1) {}
178 bool operator<(Col c) const {return id<c.id;}
179 bool operator==(Col c) const {return id==c.id;}
180 bool operator!=(Col c) const {return id==c.id;}
183 ///Refer to a row of the LP.
185 ///This type is used to refer to a row of the LP.
187 ///Its value remains valid and correct even after the addition or erase of
190 ///\todo Document what can one do with a Row (INVALID, comparing,
191 ///it is similar to Node/Edge)
195 friend class LpSolverBase;
197 typedef Value ExprValue;
198 typedef True LpSolverRow;
200 Row(const Invalid&) : id(-1) {}
202 bool operator<(Row c) const {return id<c.id;}
203 bool operator==(Row c) const {return id==c.id;}
204 bool operator!=(Row c) const {return id==c.id;}
207 ///Linear expression of variables and a constant component
209 ///This data structure strores a linear expression of the variables
210 ///(\ref Col "Col"s) and also has a constant component.
212 ///There are several ways to access and modify the contents of this
214 ///- Its it fully compatible with \c std::map<Col,double>, so for expamle
215 ///if \c e is an Expr and \c v and \c w are of type \ref Col, then you can
216 ///read and modify the coefficients like
223 ///or you can also iterate through its elements.
226 ///for(LpSolverBase::Expr::iterator i=e.begin();i!=e.end();++i)
229 ///(This code computes the sum of all coefficients).
230 ///- Numbers (<tt>double</tt>'s)
231 ///and variables (\ref Col "Col"s) directly convert to an
232 ///\ref Expr and the usual linear operations are defined so
235 ///2*v-3.12*(v-w/2)+2
236 ///v*2.1+(3*v+(v*12+w+6)*3)/2
238 ///are valid \ref Expr "Expr"essions.
239 ///The usual assignment operations are also defined.
242 ///e+=2*v-3.12*(v-w/2)+2;
246 ///- The constant member can be set and read by \ref constComp()
249 ///double c=e.constComp();
252 ///\note \ref clear() not only sets all coefficients to 0 but also
253 ///clears the constant components.
257 class Expr : public std::map<Col,Value>
260 typedef LpSolverBase::Col Key;
261 typedef LpSolverBase::Value Value;
264 typedef std::map<Col,Value> Base;
268 typedef True IsLinExpression;
270 Expr() : Base(), const_comp(0) { }
272 Expr(const Key &v) : const_comp(0) {
273 Base::insert(std::make_pair(v, 1));
276 Expr(const Value &v) : const_comp(v) {}
278 void set(const Key &v,const Value &c) {
279 Base::insert(std::make_pair(v, c));
282 Value &constComp() { return const_comp; }
284 const Value &constComp() const { return const_comp; }
286 ///Removes the components with zero coefficient.
288 for (Base::iterator i=Base::begin(); i!=Base::end();) {
291 if ((*i).second==0) Base::erase(i);
296 ///Sets all coefficients and the constant component to 0.
303 Expr &operator+=(const Expr &e) {
304 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
305 (*this)[j->first]+=j->second;
306 ///\todo it might be speeded up using "hints"
307 const_comp+=e.const_comp;
311 Expr &operator-=(const Expr &e) {
312 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
313 (*this)[j->first]-=j->second;
314 const_comp-=e.const_comp;
318 Expr &operator*=(const Value &c) {
319 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
325 Expr &operator/=(const Value &c) {
326 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
335 ///This data stucture represents a linear constraint in the LP.
336 ///Basically it is a linear expression with a lower or an upper bound
337 ///(or both). These parts of the constraint can be obtained by the member
338 ///functions \ref expr(), \ref lowerBound() and \ref upperBound(),
340 ///There are two ways to construct a constraint.
341 ///- You can set the linear expression and the bounds directly
342 /// by the functions above.
343 ///- The operators <tt>\<=</tt>, <tt>==</tt> and <tt>\>=</tt>
344 /// are defined between expressions, or even between constraints whenever
345 /// it makes sense. Therefore if \c e and \c f are linear expressions and
346 /// \c s and \c t are numbers, then the followings are valid expressions
347 /// and thus they can be used directly e.g. in \ref addRow() whenever
355 ///\warning The validity of a constraint is checked only at run time, so
356 ///e.g. \ref addRow(<tt>x[1]\<=x[2]<=5</tt>) will compile, but will throw a
357 ///\ref LogicError exception.
361 typedef LpSolverBase::Expr Expr;
362 typedef Expr::Key Key;
363 typedef Expr::Value Value;
365 // static const Value INF;
366 // static const Value NaN;
373 Constr() : _expr(), _lb(NaN), _ub(NaN) {}
375 Constr(Value lb,const Expr &e,Value ub) :
376 _expr(e), _lb(lb), _ub(ub) {}
378 Constr(const Expr &e,Value ub) :
379 _expr(e), _lb(NaN), _ub(ub) {}
381 Constr(Value lb,const Expr &e) :
382 _expr(e), _lb(lb), _ub(NaN) {}
384 Constr(const Expr &e) :
385 _expr(e), _lb(NaN), _ub(NaN) {}
393 ///Reference to the linear expression
394 Expr &expr() { return _expr; }
395 ///Cont reference to the linear expression
396 const Expr &expr() const { return _expr; }
397 ///Reference to the lower bound.
400 ///- \ref INF "INF": the constraint is lower unbounded.
401 ///- \ref NaN "NaN": lower bound has not been set.
402 ///- finite number: the lower bound
403 Value &lowerBound() { return _lb; }
404 ///The const version of \ref lowerBound()
405 const Value &lowerBound() const { return _lb; }
406 ///Reference to the upper bound.
409 ///- \ref INF "INF": the constraint is upper unbounded.
410 ///- \ref NaN "NaN": upper bound has not been set.
411 ///- finite number: the upper bound
412 Value &upperBound() { return _ub; }
413 ///The const version of \ref upperBound()
414 const Value &upperBound() const { return _ub; }
415 ///Is the constraint lower bounded?
416 bool lowerBounded() const {
420 ///Is the constraint upper bounded?
421 bool upperBounded() const {
427 ///Linear expression of rows
429 ///This data structure represents a column of the matrix,
430 ///thas is it strores a linear expression of the dual variables
431 ///(\ref Row "Row"s).
433 ///There are several ways to access and modify the contents of this
435 ///- Its it fully compatible with \c std::map<Row,double>, so for expamle
436 ///if \c e is an DualExpr and \c v
437 ///and \c w are of type \ref Row, then you can
438 ///read and modify the coefficients like
445 ///or you can also iterate through its elements.
448 ///for(LpSolverBase::DualExpr::iterator i=e.begin();i!=e.end();++i)
451 ///(This code computes the sum of all coefficients).
452 ///- Numbers (<tt>double</tt>'s)
453 ///and variables (\ref Row "Row"s) directly convert to an
454 ///\ref DualExpr and the usual linear operations are defined so
458 ///v*2.1+(3*v+(v*12+w)*3)/2
460 ///are valid \ref DualExpr "DualExpr"essions.
461 ///The usual assignment operations are also defined.
464 ///e+=2*v-3.12*(v-w/2);
471 class DualExpr : public std::map<Row,Value>
474 typedef LpSolverBase::Row Key;
475 typedef LpSolverBase::Value Value;
478 typedef std::map<Row,Value> Base;
481 typedef True IsLinExpression;
483 DualExpr() : Base() { }
485 DualExpr(const Key &v) {
486 Base::insert(std::make_pair(v, 1));
489 void set(const Key &v,const Value &c) {
490 Base::insert(std::make_pair(v, c));
493 ///Removes the components with zero coefficient.
495 for (Base::iterator i=Base::begin(); i!=Base::end();) {
498 if ((*i).second==0) Base::erase(i);
503 ///Sets all coefficients to 0.
509 DualExpr &operator+=(const DualExpr &e) {
510 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
511 (*this)[j->first]+=j->second;
512 ///\todo it might be speeded up using "hints"
516 DualExpr &operator-=(const DualExpr &e) {
517 for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
518 (*this)[j->first]-=j->second;
522 DualExpr &operator*=(const Value &c) {
523 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
528 DualExpr &operator/=(const Value &c) {
529 for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
540 //Abstract virtual functions
541 virtual LpSolverBase &_newLp() = 0;
542 virtual LpSolverBase &_copyLp(){
543 ///\todo This should be implemented here, too, when we have problem retrieving routines. It can be overriden.
546 LpSolverBase & newlp(_newLp());
548 //return *(LpSolverBase*)0;
551 virtual int _addCol() = 0;
552 virtual int _addRow() = 0;
553 virtual void _eraseCol(int col) = 0;
554 virtual void _eraseRow(int row) = 0;
555 virtual void _setRowCoeffs(int i,
558 Value const * values ) = 0;
559 virtual void _setColCoeffs(int i,
562 Value const * values ) = 0;
563 virtual void _setCoeff(int row, int col, Value value) = 0;
564 virtual void _setColLowerBound(int i, Value value) = 0;
565 virtual void _setColUpperBound(int i, Value value) = 0;
566 // virtual void _setRowLowerBound(int i, Value value) = 0;
567 // virtual void _setRowUpperBound(int i, Value value) = 0;
568 virtual void _setRowBounds(int i, Value lower, Value upper) = 0;
569 virtual void _setObjCoeff(int i, Value obj_coef) = 0;
570 virtual void _clearObj()=0;
571 // virtual void _setObj(int length,
572 // int const * indices,
573 // Value const * values ) = 0;
574 virtual SolveExitStatus _solve() = 0;
575 virtual Value _getPrimal(int i) = 0;
576 virtual Value _getPrimalValue() = 0;
577 virtual SolutionStatus _getPrimalStatus() = 0;
578 virtual SolutionStatus _getDualStatus() = 0;
579 ///\todo This could be implemented here, too, using _getPrimalStatus() and
581 virtual ProblemTypes _getProblemType() = 0;
583 virtual void _setMax() = 0;
584 virtual void _setMin() = 0;
586 //Own protected stuff
588 //Constant component of the objective function
589 Value obj_const_comp;
597 LpSolverBase() : obj_const_comp(0) {}
600 virtual ~LpSolverBase() {}
602 ///Creates a new LP problem
603 LpSolverBase &newLp() {return _newLp();}
604 ///Makes a copy of the LP problem
605 LpSolverBase ©Lp() {return _copyLp();}
607 ///\name Build up and modify the LP
611 ///Add a new empty column (i.e a new variable) to the LP
612 Col addCol() { Col c; c.id=cols.insert(_addCol()); return c;}
614 ///\brief Adds several new columns
615 ///(i.e a variables) at once
617 ///This magic function takes a container as its argument
618 ///and fills its elements
619 ///with new columns (i.e. variables)
621 ///- a standard STL compatible iterable container with
622 ///\ref Col as its \c values_type
625 ///std::vector<LpSolverBase::Col>
626 ///std::list<LpSolverBase::Col>
628 ///- a standard STL compatible iterable container with
629 ///\ref Col as its \c mapped_type
632 ///std::map<AnyType,LpSolverBase::Col>
634 ///- an iterable lemon \ref concept::WriteMap "write map" like
636 ///ListGraph::NodeMap<LpSolverBase::Col>
637 ///ListGraph::EdgeMap<LpSolverBase::Col>
639 ///\return The number of the created column.
642 int addColSet(T &t) { return 0;}
645 typename enable_if<typename T::value_type::LpSolverCol,int>::type
646 addColSet(T &t,dummy<0> = 0) {
648 for(typename T::iterator i=t.begin();i!=t.end();++i) {*i=addCol();s++;}
652 typename enable_if<typename T::value_type::second_type::LpSolverCol,
654 addColSet(T &t,dummy<1> = 1) {
656 for(typename T::iterator i=t.begin();i!=t.end();++i) {
663 typename enable_if<typename T::ValueSet::value_type::LpSolverCol,
665 addColSet(T &t,dummy<2> = 2) {
666 ///\bug <tt>return addColSet(t.valueSet());</tt> should also work.
668 for(typename T::ValueSet::iterator i=t.valueSet().begin();
669 i!=t.valueSet().end();
679 ///Set a column (i.e a dual constraint) of the LP
681 ///\param c is the column to be modified
682 ///\param e is a dual linear expression (see \ref DualExpr)
683 ///\bug This is a temporary function. The interface will change to
685 void setCol(Col c,const DualExpr &e) {
686 std::vector<int> indices;
687 std::vector<Value> values;
688 indices.push_back(0);
690 for(DualExpr::const_iterator i=e.begin(); i!=e.end(); ++i)
691 if((*i).second!=0) { ///\bug EPSILON would be necessary here!!!
692 indices.push_back(cols.floatingId((*i).first.id));
693 values.push_back((*i).second);
695 _setColCoeffs(cols.floatingId(c.id),indices.size()-1,
696 &indices[0],&values[0]);
699 ///Add a new column to the LP
701 ///\param e is a dual linear expression (see \ref DualExpr)
702 ///\param obj is the corresponding component of the objective
703 ///function. It is 0 by default.
704 ///\return The created column.
705 ///\bug This is a temportary function. The interface will change to
707 Col addCol(const DualExpr &e, Value obj=0) {
714 ///Add a new empty row (i.e a new constraint) to the LP
716 ///This function adds a new empty row (i.e a new constraint) to the LP.
717 ///\return The created row
718 Row addRow() { Row r; r.id=rows.insert(_addRow()); return r;}
720 ///\brief Add several new rows
721 ///(i.e a constraints) at once
723 ///This magic function takes a container as its argument
724 ///and fills its elements
725 ///with new row (i.e. variables)
727 ///- a standard STL compatible iterable container with
728 ///\ref Row as its \c values_type
731 ///std::vector<LpSolverBase::Row>
732 ///std::list<LpSolverBase::Row>
734 ///- a standard STL compatible iterable container with
735 ///\ref Row as its \c mapped_type
738 ///std::map<AnyType,LpSolverBase::Row>
740 ///- an iterable lemon \ref concept::WriteMap "write map" like
742 ///ListGraph::NodeMap<LpSolverBase::Row>
743 ///ListGraph::EdgeMap<LpSolverBase::Row>
745 ///\return The number of rows created.
748 int addRowSet(T &t) { return 0;}
751 typename enable_if<typename T::value_type::LpSolverRow,int>::type
752 addRowSet(T &t,dummy<0> = 0) {
754 for(typename T::iterator i=t.begin();i!=t.end();++i) {*i=addRow();s++;}
758 typename enable_if<typename T::value_type::second_type::LpSolverRow,
760 addRowSet(T &t,dummy<1> = 1) {
762 for(typename T::iterator i=t.begin();i!=t.end();++i) {
769 typename enable_if<typename T::ValueSet::value_type::LpSolverRow,
771 addRowSet(T &t,dummy<2> = 2) {
772 ///\bug <tt>return addRowSet(t.valueSet());</tt> should also work.
774 for(typename T::ValueSet::iterator i=t.valueSet().begin();
775 i!=t.valueSet().end();
785 ///Set a row (i.e a constraint) of the LP
787 ///\param r is the row to be modified
788 ///\param l is lower bound (-\ref INF means no bound)
789 ///\param e is a linear expression (see \ref Expr)
790 ///\param u is the upper bound (\ref INF means no bound)
791 ///\bug This is a temportary function. The interface will change to
793 ///\todo Option to control whether a constraint with a single variable is
795 void setRow(Row r, Value l,const Expr &e, Value u) {
796 std::vector<int> indices;
797 std::vector<Value> values;
798 indices.push_back(0);
800 for(Expr::const_iterator i=e.begin(); i!=e.end(); ++i)
801 if((*i).second!=0) { ///\bug EPSILON would be necessary here!!!
802 indices.push_back(cols.floatingId((*i).first.id));
803 values.push_back((*i).second);
805 _setRowCoeffs(rows.floatingId(r.id),indices.size()-1,
806 &indices[0],&values[0]);
807 // _setRowLowerBound(rows.floatingId(r.id),l-e.constComp());
808 // _setRowUpperBound(rows.floatingId(r.id),u-e.constComp());
809 _setRowBounds(rows.floatingId(r.id),l-e.constComp(),u-e.constComp());
812 ///Set a row (i.e a constraint) of the LP
814 ///\param r is the row to be modified
815 ///\param c is a linear expression (see \ref Constr)
816 void setRow(Row r, const Constr &c) {
818 c.lowerBounded()?c.lowerBound():-INF,
820 c.upperBounded()?c.upperBound():INF);
823 ///Add a new row (i.e a new constraint) to the LP
825 ///\param l is the lower bound (-\ref INF means no bound)
826 ///\param e is a linear expression (see \ref Expr)
827 ///\param u is the upper bound (\ref INF means no bound)
828 ///\return The created row.
829 ///\bug This is a temportary function. The interface will change to
831 Row addRow(Value l,const Expr &e, Value u) {
837 ///Add a new row (i.e a new constraint) to the LP
839 ///\param c is a linear expression (see \ref Constr)
840 ///\return The created row.
841 Row addRow(const Constr &c) {
846 ///Erase a coloumn (i.e a variable) from the LP
848 ///\param c is the coloumn to be deleted
849 ///\todo Please check this
850 void eraseCol(Col c) {
851 _eraseCol(cols.floatingId(c.id));
854 ///Erase a row (i.e a constraint) from the LP
856 ///\param r is the row to be deleted
857 ///\todo Please check this
858 void eraseRow(Row r) {
859 _eraseRow(rows.floatingId(r.id));
863 ///Set an element of the coefficient matrix of the LP
865 ///\param r is the row of the element to be modified
866 ///\param c is the coloumn of the element to be modified
867 ///\param val is the new value of the coefficient
868 void setCoeff(Row r, Col c, Value val){
869 _setCoeff(rows.floatingId(r.id),cols.floatingId(c.id), val);
872 /// Set the lower bound of a column (i.e a variable)
874 /// The upper bound of a variable (column) has to be given by an
875 /// extended number of type Value, i.e. a finite number of type
876 /// Value or -\ref INF.
877 void colLowerBound(Col c, Value value) {
878 _setColLowerBound(cols.floatingId(c.id),value);
880 /// Set the upper bound of a column (i.e a variable)
882 /// The upper bound of a variable (column) has to be given by an
883 /// extended number of type Value, i.e. a finite number of type
884 /// Value or \ref INF.
885 void colUpperBound(Col c, Value value) {
886 _setColUpperBound(cols.floatingId(c.id),value);
888 /// Set the lower and the upper bounds of a column (i.e a variable)
890 /// The lower and the upper bounds of
891 /// a variable (column) have to be given by an
892 /// extended number of type Value, i.e. a finite number of type
893 /// Value, -\ref INF or \ref INF.
894 void colBounds(Col c, Value lower, Value upper) {
895 _setColLowerBound(cols.floatingId(c.id),lower);
896 _setColUpperBound(cols.floatingId(c.id),upper);
899 // /// Set the lower bound of a row (i.e a constraint)
901 // /// The lower bound of a linear expression (row) has to be given by an
902 // /// extended number of type Value, i.e. a finite number of type
903 // /// Value or -\ref INF.
904 // void rowLowerBound(Row r, Value value) {
905 // _setRowLowerBound(rows.floatingId(r.id),value);
907 // /// Set the upper bound of a row (i.e a constraint)
909 // /// The upper bound of a linear expression (row) has to be given by an
910 // /// extended number of type Value, i.e. a finite number of type
911 // /// Value or \ref INF.
912 // void rowUpperBound(Row r, Value value) {
913 // _setRowUpperBound(rows.floatingId(r.id),value);
916 /// Set the lower and the upper bounds of a row (i.e a constraint)
918 /// The lower and the upper bounds of
919 /// a constraint (row) have to be given by an
920 /// extended number of type Value, i.e. a finite number of type
921 /// Value, -\ref INF or \ref INF.
922 void rowBounds(Row c, Value lower, Value upper) {
923 _setRowBounds(rows.floatingId(c.id),lower, upper);
924 // _setRowUpperBound(rows.floatingId(c.id),upper);
927 ///Set an element of the objective function
928 void objCoeff(Col c, Value v) {_setObjCoeff(cols.floatingId(c.id),v); };
929 ///Set the objective function
931 ///\param e is a linear expression of type \ref Expr.
932 ///\bug The previous objective function is not cleared!
933 void setObj(Expr e) {
935 for (Expr::iterator i=e.begin(); i!=e.end(); ++i)
936 objCoeff((*i).first,(*i).second);
937 obj_const_comp=e.constComp();
941 void max() { _setMax(); }
943 void min() { _setMin(); }
949 ///\name Solve the LP
953 ///\e Solve the LP problem at hand
955 ///\return The result of the optimization procedure. Possible values and their meanings can be found in the documentation of \ref SolveExitStatus.
957 ///\todo Which method is used to solve the problem
958 SolveExitStatus solve() { return _solve(); }
962 ///\name Obtain the solution
966 /// The status of the primal problem (the original LP problem)
967 SolutionStatus primalStatus() {
968 return _getPrimalStatus();
971 /// The status of the dual (of the original LP) problem
972 SolutionStatus dualStatus() {
973 return _getDualStatus();
976 ///The type of the original LP problem
977 ProblemTypes problemType() {
978 return _getProblemType();
982 Value primal(Col c) { return _getPrimal(cols.floatingId(c.id)); }
987 ///- \ref INF or -\ref INF means either infeasibility or unboundedness
988 /// of the primal problem, depending on whether we minimize or maximize.
989 ///- \ref NaN if no primal solution is found.
990 ///- The (finite) objective value if an optimal solution is found.
991 Value primalValue() { return _getPrimalValue()+obj_const_comp;}
998 ///\relates LpSolverBase::Expr
1000 inline LpSolverBase::Expr operator+(const LpSolverBase::Expr &a,
1001 const LpSolverBase::Expr &b)
1003 LpSolverBase::Expr tmp(a);
1004 tmp+=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1009 ///\relates LpSolverBase::Expr
1011 inline LpSolverBase::Expr operator-(const LpSolverBase::Expr &a,
1012 const LpSolverBase::Expr &b)
1014 LpSolverBase::Expr tmp(a);
1015 tmp-=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1020 ///\relates LpSolverBase::Expr
1022 inline LpSolverBase::Expr operator*(const LpSolverBase::Expr &a,
1023 const LpSolverBase::Value &b)
1025 LpSolverBase::Expr tmp(a);
1026 tmp*=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1032 ///\relates LpSolverBase::Expr
1034 inline LpSolverBase::Expr operator*(const LpSolverBase::Value &a,
1035 const LpSolverBase::Expr &b)
1037 LpSolverBase::Expr tmp(b);
1038 tmp*=a; ///\todo Doesn't STL have some special 'merge' algorithm?
1043 ///\relates LpSolverBase::Expr
1045 inline LpSolverBase::Expr operator/(const LpSolverBase::Expr &a,
1046 const LpSolverBase::Value &b)
1048 LpSolverBase::Expr tmp(a);
1049 tmp/=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1055 ///\relates LpSolverBase::Constr
1057 inline LpSolverBase::Constr operator<=(const LpSolverBase::Expr &e,
1058 const LpSolverBase::Expr &f)
1060 return LpSolverBase::Constr(-LpSolverBase::INF,e-f,0);
1065 ///\relates LpSolverBase::Constr
1067 inline LpSolverBase::Constr operator<=(const LpSolverBase::Value &e,
1068 const LpSolverBase::Expr &f)
1070 return LpSolverBase::Constr(e,f);
1075 ///\relates LpSolverBase::Constr
1077 inline LpSolverBase::Constr operator<=(const LpSolverBase::Expr &e,
1078 const LpSolverBase::Value &f)
1080 return LpSolverBase::Constr(e,f);
1085 ///\relates LpSolverBase::Constr
1087 inline LpSolverBase::Constr operator>=(const LpSolverBase::Expr &e,
1088 const LpSolverBase::Expr &f)
1090 return LpSolverBase::Constr(-LpSolverBase::INF,f-e,0);
1096 ///\relates LpSolverBase::Constr
1098 inline LpSolverBase::Constr operator>=(const LpSolverBase::Value &e,
1099 const LpSolverBase::Expr &f)
1101 return LpSolverBase::Constr(f,e);
1107 ///\relates LpSolverBase::Constr
1109 inline LpSolverBase::Constr operator>=(const LpSolverBase::Expr &e,
1110 const LpSolverBase::Value &f)
1112 return LpSolverBase::Constr(f,e);
1117 ///\relates LpSolverBase::Constr
1119 inline LpSolverBase::Constr operator==(const LpSolverBase::Expr &e,
1120 const LpSolverBase::Expr &f)
1122 return LpSolverBase::Constr(0,e-f,0);
1127 ///\relates LpSolverBase::Constr
1129 inline LpSolverBase::Constr operator<=(const LpSolverBase::Value &n,
1130 const LpSolverBase::Constr&c)
1132 LpSolverBase::Constr tmp(c);
1133 ///\todo Create an own exception type.
1134 if(!isnan(tmp.lowerBound())) throw LogicError();
1135 else tmp.lowerBound()=n;
1140 ///\relates LpSolverBase::Constr
1142 inline LpSolverBase::Constr operator<=(const LpSolverBase::Constr& c,
1143 const LpSolverBase::Value &n)
1145 LpSolverBase::Constr tmp(c);
1146 ///\todo Create an own exception type.
1147 if(!isnan(tmp.upperBound())) throw LogicError();
1148 else tmp.upperBound()=n;
1154 ///\relates LpSolverBase::Constr
1156 inline LpSolverBase::Constr operator>=(const LpSolverBase::Value &n,
1157 const LpSolverBase::Constr&c)
1159 LpSolverBase::Constr tmp(c);
1160 ///\todo Create an own exception type.
1161 if(!isnan(tmp.upperBound())) throw LogicError();
1162 else tmp.upperBound()=n;
1167 ///\relates LpSolverBase::Constr
1169 inline LpSolverBase::Constr operator>=(const LpSolverBase::Constr& c,
1170 const LpSolverBase::Value &n)
1172 LpSolverBase::Constr tmp(c);
1173 ///\todo Create an own exception type.
1174 if(!isnan(tmp.lowerBound())) throw LogicError();
1175 else tmp.lowerBound()=n;
1181 ///\relates LpSolverBase::DualExpr
1183 inline LpSolverBase::DualExpr operator+(const LpSolverBase::DualExpr &a,
1184 const LpSolverBase::DualExpr &b)
1186 LpSolverBase::DualExpr tmp(a);
1187 tmp+=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1192 ///\relates LpSolverBase::DualExpr
1194 inline LpSolverBase::DualExpr operator-(const LpSolverBase::DualExpr &a,
1195 const LpSolverBase::DualExpr &b)
1197 LpSolverBase::DualExpr tmp(a);
1198 tmp-=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1203 ///\relates LpSolverBase::DualExpr
1205 inline LpSolverBase::DualExpr operator*(const LpSolverBase::DualExpr &a,
1206 const LpSolverBase::Value &b)
1208 LpSolverBase::DualExpr tmp(a);
1209 tmp*=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1215 ///\relates LpSolverBase::DualExpr
1217 inline LpSolverBase::DualExpr operator*(const LpSolverBase::Value &a,
1218 const LpSolverBase::DualExpr &b)
1220 LpSolverBase::DualExpr tmp(b);
1221 tmp*=a; ///\todo Doesn't STL have some special 'merge' algorithm?
1226 ///\relates LpSolverBase::DualExpr
1228 inline LpSolverBase::DualExpr operator/(const LpSolverBase::DualExpr &a,
1229 const LpSolverBase::Value &b)
1231 LpSolverBase::DualExpr tmp(a);
1232 tmp/=b; ///\todo Doesn't STL have some special 'merge' algorithm?
1239 #endif //LEMON_LP_BASE_H