lemon-1.2: comparison lemon/lp

equal deleted inserted replaced

-:76647be8083f
+:04ffa1315598
 #include<vector>
 #include<map>
 #include<limits>
 #include<lemon/math.h>
+#include<lemon/error.h>
+#include<lemon/assert.h>
 #include<lemon/core.h>
-#include<lemon/bits/lp_id.h>
+#include<lemon/bits/solver_bits.h>
 ///\file
 ///\brief The interface of the LP solver interface.
 ///\ingroup lp_group
 namespace lemon {
-/// Function to decide whether a floating point value is finite or not.
+///Common base class for LP and MIP solvers
-/// Retruns true if the argument is not infinity, minus infinity or NaN.
+///Usually this class is not used directly, please use one of the concrete
-/// It does the same as the isfinite() function defined by C99.
+///implementations of the solver interface.
-template <typename T>
-bool isFinite(T value)
-{
-typedef std::numeric_limits<T> Lim;
-if ((Lim::has_infinity && (value == Lim::infinity() || value ==
--Lim::infinity())) ||
-((Lim::has_quiet_NaN || Lim::has_signaling_NaN) && value != value))
-{
-return false;
-}
-return true;
-}
-///Common base class for LP solvers
-///\todo Much more docs
 ///\ingroup lp_group
-class LpSolverBase {
+class LpBase {
 protected:
-_lp_bits::LpId rows;
+_solver_bits::VarIndex rows;
-_lp_bits::LpId cols;
+_solver_bits::VarIndex cols;
 public:
 ///Possible outcomes of an LP solving procedure
 enum SolveExitStatus {
 ///Any other case (including the case when some user specified
 ///limit has been exceeded)
 UNSOLVED = 1
 };
-///\e
+///Direction of the optimization
-enum SolutionStatus {
+enum Sense {
-///Feasible solution hasn't been found (but may exist).
+/// Minimization
+MIN,
-///\todo NOTFOUND might be a better name.
+/// Maximization
-///
+MAX
-UNDEFINED = 0,
-///The problem has no feasible solution
-INFEASIBLE = 1,
-///Feasible solution found
-FEASIBLE = 2,
-///Optimal solution exists and found
-OPTIMAL = 3,
-///The cost function is unbounded
-///\todo Give a feasible solution and an infinite ray (and the
-///corresponding bases)
-INFINITE = 4
-};
-///\e The type of the investigated LP problem
-enum ProblemTypes {
-///Primal-dual feasible
-PRIMAL_DUAL_FEASIBLE = 0,
-///Primal feasible dual infeasible
-PRIMAL_FEASIBLE_DUAL_INFEASIBLE = 1,
-///Primal infeasible dual feasible
-PRIMAL_INFEASIBLE_DUAL_FEASIBLE = 2,
-///Primal-dual infeasible
-PRIMAL_DUAL_INFEASIBLE = 3,
-///Could not determine so far
-UNKNOWN = 4
 };
 ///The floating point type used by the solver
 typedef double Value;
 ///The infinity constant
 static const Value INF;
 ///The not a number constant
 static const Value NaN;
-static inline bool isNaN(const Value& v) { return v!=v; }
 friend class Col;
 friend class ColIt;
 friend class Row;
+friend class RowIt;
 ///Refer to a column of the LP.
 ///This type is used to refer to a column of the LP.
 ///
 ///Its value remains valid and correct even after the addition or erase of
 ///other columns.
 ///
-///\todo Document what can one do with a Col (INVALID, comparing,
+///\note This class is similar to other Item types in LEMON, like
-///it is similar to Node/Edge)
+///Node and Arc types in digraph.
 class Col {
+friend class LpBase;
 protected:
-int id;
+int _id;
-friend class LpSolverBase;
+explicit Col(int id) : _id(id) {}
-friend class MipSolverBase;
-explicit Col(int _id) : id(_id) {}
 public:
 typedef Value ExprValue;
-typedef True LpSolverCol;
+typedef True LpCol;
+/// Default constructor
+/// \warning The default constructor sets the Col to an
+/// undefined value.
 Col() {}
-Col(const Invalid&) : id(-1) {}
+/// Invalid constructor \& conversion.
-bool operator< (Col c) const  {return id< c.id;}
-bool operator> (Col c) const  {return id> c.id;}
+/// This constructor initializes the Col to be invalid.
-bool operator==(Col c) const  {return id==c.id;}
+/// \sa Invalid for more details.
-bool operator!=(Col c) const  {return id!=c.id;}
+Col(const Invalid&) : _id(-1) {}
+/// Equality operator
+/// Two \ref Col "Col"s are equal if and only if they point to
+/// the same LP column or both are invalid.
+bool operator==(Col c) const  {return _id == c._id;}
+/// Inequality operator
+/// \sa operator==(Col c)
+///
+bool operator!=(Col c) const  {return _id != c._id;}
+/// Artificial ordering operator.
+/// To allow the use of this object in std::map or similar
+/// associative container we require this.
+///
+/// \note This operator only have to define some strict ordering of
+/// the items; this order has nothing to do with the iteration
+/// ordering of the items.
+bool operator<(Col c) const  {return _id < c._id;}
 };
+///Iterator for iterate over the columns of an LP problem
+/// Its usage is quite simple, for example you can count the number
+/// of columns in an LP \c lp:
+///\code
+/// int count=0;
+/// for (LpBase::ColIt c(lp); c!=INVALID; ++c) ++count;
+///\endcode
 class ColIt : public Col {
-const LpSolverBase *_lp;
+const LpBase *_solver;
 public:
+/// Default constructor
+/// \warning The default constructor sets the iterator
+/// to an undefined value.
 ColIt() {}
-ColIt(const LpSolverBase &lp) : _lp(&lp)
+/// Sets the iterator to the first Col
+/// Sets the iterator to the first Col.
+///
+ColIt(const LpBase &solver) : _solver(&solver)
 {
-_lp->cols.firstFix(id);
+_solver->cols.firstItem(_id);
 }
+/// Invalid constructor \& conversion
+/// Initialize the iterator to be invalid.
+/// \sa Invalid for more details.
 ColIt(const Invalid&) : Col(INVALID) {}
+/// Next column
+/// Assign the iterator to the next column.
+///
 ColIt &operator++()
 {
-_lp->cols.nextFix(id);
+_solver->cols.nextItem(_id);
 return *this;
 }
 };
-static int id(const Col& col) { return col.id; }
+/// \brief Returns the ID of the column.
+static int id(const Col& col) { return col._id; }
+/// \brief Returns the column with the given ID.
+///
+/// \pre The argument should be a valid column ID in the LP problem.
+static Col colFromId(int id) { return Col(id); }
 ///Refer to a row of the LP.
 ///This type is used to refer to a row of the LP.
 ///
 ///Its value remains valid and correct even after the addition or erase of
 ///other rows.
 ///
-///\todo Document what can one do with a Row (INVALID, comparing,
+///\note This class is similar to other Item types in LEMON, like
-///it is similar to Node/Edge)
+///Node and Arc types in digraph.
 class Row {
+friend class LpBase;
 protected:
-int id;
+int _id;
-friend class LpSolverBase;
+explicit Row(int id) : _id(id) {}
-explicit Row(int _id) : id(_id) {}
 public:
 typedef Value ExprValue;
-typedef True LpSolverRow;
+typedef True LpRow;
+/// Default constructor
+/// \warning The default constructor sets the Row to an
+/// undefined value.
 Row() {}
-Row(const Invalid&) : id(-1) {}
+/// Invalid constructor \& conversion.
-bool operator< (Row c) const  {return id< c.id;}
+/// This constructor initializes the Row to be invalid.
-bool operator> (Row c) const  {return id> c.id;}
+/// \sa Invalid for more details.
-bool operator==(Row c) const  {return id==c.id;}
+Row(const Invalid&) : _id(-1) {}
-bool operator!=(Row c) const  {return id!=c.id;}
+/// Equality operator
+/// Two \ref Row "Row"s are equal if and only if they point to
+/// the same LP row or both are invalid.
+bool operator==(Row r) const  {return _id == r._id;}
+/// Inequality operator
+/// \sa operator==(Row r)
+///
+bool operator!=(Row r) const  {return _id != r._id;}
+/// Artificial ordering operator.
+/// To allow the use of this object in std::map or similar
+/// associative container we require this.
+///
+/// \note This operator only have to define some strict ordering of
+/// the items; this order has nothing to do with the iteration
+/// ordering of the items.
+bool operator<(Row r) const  {return _id < r._id;}
 };
+///Iterator for iterate over the rows of an LP problem
+/// Its usage is quite simple, for example you can count the number
+/// of rows in an LP \c lp:
+///\code
+/// int count=0;
+/// for (LpBase::RowIt c(lp); c!=INVALID; ++c) ++count;
+///\endcode
 class RowIt : public Row {
-const LpSolverBase *_lp;
+const LpBase *_solver;
 public:
+/// Default constructor
+/// \warning The default constructor sets the iterator
+/// to an undefined value.
 RowIt() {}
-RowIt(const LpSolverBase &lp) : _lp(&lp)
+/// Sets the iterator to the first Row
+/// Sets the iterator to the first Row.
+///
+RowIt(const LpBase &solver) : _solver(&solver)
 {
-_lp->rows.firstFix(id);
+_solver->rows.firstItem(_id);
 }
+/// Invalid constructor \& conversion
+/// Initialize the iterator to be invalid.
+/// \sa Invalid for more details.
 RowIt(const Invalid&) : Row(INVALID) {}
+/// Next row
+/// Assign the iterator to the next row.
+///
 RowIt &operator++()
 {
-_lp->rows.nextFix(id);
+_solver->rows.nextItem(_id);
 return *this;
 }
 };
-static int id(const Row& row) { return row.id; }
+/// \brief Returns the ID of the row.
+static int id(const Row& row) { return row._id; }
-protected:
+/// \brief Returns the row with the given ID.
+///
-int _lpId(const Col& c) const {
+/// \pre The argument should be a valid row ID in the LP problem.
-return cols.floatingId(id(c));
+static Row rowFromId(int id) { return Row(id); }
-}
-int _lpId(const Row& r) const {
-return rows.floatingId(id(r));
-}
-Col _item(int i, Col) const {
-return Col(cols.fixId(i));
-}
-Row _item(int i, Row) const {
-return Row(rows.fixId(i));
-}
 public:
 ///Linear expression of variables and a constant component
 ///This data structure stores a linear expression of the variables
 ///(\ref Col "Col"s) and also has a constant component.
 ///
 ///There are several ways to access and modify the contents of this
 ///container.
-///- Its it fully compatible with \c std::map<Col,double>, so for expamle
-///if \c e is an Expr and \c v and \c w are of type \ref Col, then you can
-///read and modify the coefficients like
-///these.
 ///\code
 ///e[v]=5;
 ///e[v]+=12;
 ///e.erase(v);
 ///\endcode
 ///or you can also iterate through its elements.
 ///\code
 ///double s=0;
-///for(LpSolverBase::Expr::iterator i=e.begin();i!=e.end();++i)
+///for(LpBase::Expr::ConstCoeffIt i(e);i!=INVALID;++i)
-///  s+=i->second;
+///  s+=*i * primal(i);
 ///\endcode
-///(This code computes the sum of all coefficients).
+///(This code computes the primal value of the expression).
 ///- Numbers (<tt>double</tt>'s)
 ///and variables (\ref Col "Col"s) directly convert to an
 ///\ref Expr and the usual linear operations are defined, so
 ///\code
 ///v+w
 ///2*v-3.12*(v-w/2)+2
 ///v*2.1+(3*v+(v*12+w+6)*3)/2
 ///\endcode
-///are valid \ref Expr "Expr"essions.
+///are valid expressions.
 ///The usual assignment operations are also defined.
 ///\code
 ///e=v+w;
 ///e+=2*v-3.12*(v-w/2)+2;
 ///e*=3.4;
 ///e/=5;
 ///\endcode
-///- The constant member can be set and read by \ref constComp()
+///- The constant member can be set and read by dereference
+///  operator (unary *)
+///
 ///\code
-///e.constComp()=12;
+///*e=12;
-///double c=e.constComp();
+///double c=*e;
 ///\endcode
 ///
-///\note \ref clear() not only sets all coefficients to 0 but also
-///clears the constant components.
-///
 ///\sa Constr
-///
+class Expr {
-class Expr : public std::map<Col,Value>
+friend class LpBase;
-{
 public:
-typedef LpSolverBase::Col Key;
+/// The key type of the expression
-typedef LpSolverBase::Value Value;
+typedef LpBase::Col Key;
+/// The value type of the expression
+typedef LpBase::Value Value;
 protected:
-typedef std::map<Col,Value> Base;
 Value const_comp;
+std::map<int, Value> comps;
 public:
-typedef True IsLinExpression;
+typedef True SolverExpr;
-///\e
+/// Default constructor
-Expr() : Base(), const_comp(0) { }
-///\e
+/// Construct an empty expression, the coefficients and
-Expr(const Key &v) : const_comp(0) {
+/// the constant component are initialized to zero.
-Base::insert(std::make_pair(v, 1));
+Expr() : const_comp(0) {}
-}
+/// Construct an expression from a column
-///\e
+/// Construct an expression, which has a term with \c c variable
+/// and 1.0 coefficient.
+Expr(const Col &c) : const_comp(0) {
+typedef std::map<int, Value>::value_type pair_type;
+comps.insert(pair_type(id(c), 1));
+}
+/// Construct an expression from a constant
+/// Construct an expression, which's constant component is \c v.
+///
 Expr(const Value &v) : const_comp(v) {}
-///\e
+/// Returns the coefficient of the column
-void set(const Key &v,const Value &c) {
+Value operator[](const Col& c) const {
-Base::insert(std::make_pair(v, c));
+std::map<int, Value>::const_iterator it=comps.find(id(c));
-}
+if (it != comps.end()) {
-///\e
+return it->second;
-Value &constComp() { return const_comp; }
+} else {
-///\e
+return 0;
-const Value &constComp() const { return const_comp; }
-///Removes the components with zero coefficient.
-void simplify() {
-for (Base::iterator i=Base::begin(); i!=Base::end();) {
-Base::iterator j=i;
-++j;
-if ((*i).second==0) Base::erase(i);
-i=j;
 }
 }
+/// Returns the coefficient of the column
-void simplify() const {
+Value& operator[](const Col& c) {
-const_cast<Expr*>(this)->simplify();
+return comps[id(c)];
 }
+/// Sets the coefficient of the column
-///Removes the coefficients closer to zero than \c tolerance.
+void set(const Col &c, const Value &v) {
-void simplify(double &tolerance) {
+if (v != 0.0) {
-for (Base::iterator i=Base::begin(); i!=Base::end();) {
+typedef std::map<int, Value>::value_type pair_type;
-Base::iterator j=i;
+comps.insert(pair_type(id(c), v));
-++j;
+} else {
-if (std::fabs((*i).second)<tolerance) Base::erase(i);
+comps.erase(id(c));
-i=j;
 }
+}
+/// Returns the constant component of the expression
+Value& operator*() { return const_comp; }
+/// Returns the constant component of the expression
+const Value& operator*() const { return const_comp; }
+/// \brief Removes the coefficients which's absolute value does
+/// not exceed \c epsilon. It also sets to zero the constant
+/// component, if it does not exceed epsilon in absolute value.
+void simplify(Value epsilon = 0.0) {
+std::map<int, Value>::iterator it=comps.begin();
+while (it != comps.end()) {
+std::map<int, Value>::iterator jt=it;
+++jt;
+if (std::fabs((*it).second) <= epsilon) comps.erase(it);
+it=jt;
+}
+if (std::fabs(const_comp) <= epsilon) const_comp = 0;
+}
+void simplify(Value epsilon = 0.0) const {
+const_cast<Expr*>(this)->simplify(epsilon);
 }
 ///Sets all coefficients and the constant component to 0.
 void clear() {
-Base::clear();
+comps.clear();
 const_comp=0;
 }
-///\e
+///Compound assignment
 Expr &operator+=(const Expr &e) {
-for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
+for (std::map<int, Value>::const_iterator it=e.comps.begin();
-(*this)[j->first]+=j->second;
+it!=e.comps.end(); ++it)
+comps[it->first]+=it->second;
 const_comp+=e.const_comp;
 return *this;
 }
-///\e
+///Compound assignment
 Expr &operator-=(const Expr &e) {
-for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
+for (std::map<int, Value>::const_iterator it=e.comps.begin();
-(*this)[j->first]-=j->second;
+it!=e.comps.end(); ++it)
+comps[it->first]-=it->second;
 const_comp-=e.const_comp;
 return *this;
 }
-///\e
+///Multiply with a constant
-Expr &operator*=(const Value &c) {
+Expr &operator*=(const Value &v) {
-for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
+for (std::map<int, Value>::iterator it=comps.begin();
-j->second*=c;
+it!=comps.end(); ++it)
-const_comp*=c;
+it->second*=v;
+const_comp*=v;
 return *this;
 }
-///\e
+///Division with a constant
 Expr &operator/=(const Value &c) {
-for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
+for (std::map<int, Value>::iterator it=comps.begin();
-j->second/=c;
+it!=comps.end(); ++it)
+it->second/=c;
 const_comp/=c;
 return *this;
 }
+///Iterator over the expression
+///The iterator iterates over the terms of the expression.
+///
+///\code
+///double s=0;
+///for(LpBase::Expr::CoeffIt i(e);i!=INVALID;++i)
+///  s+= *i * primal(i);
+///\endcode
+class CoeffIt {
+private:
+std::map<int, Value>::iterator _it, _end;
+public:
+/// Sets the iterator to the first term
+/// Sets the iterator to the first term of the expression.
+///
+CoeffIt(Expr& e)
+: _it(e.comps.begin()), _end(e.comps.end()){}
+/// Convert the iterator to the column of the term
+operator Col() const {
+return colFromId(_it->first);
+}
+/// Returns the coefficient of the term
+Value& operator*() { return _it->second; }
+/// Returns the coefficient of the term
+const Value& operator*() const { return _it->second; }
+/// Next term
+/// Assign the iterator to the next term.
+///
+CoeffIt& operator++() { ++_it; return *this; }
+/// Equality operator
+bool operator==(Invalid) const { return _it == _end; }
+/// Inequality operator
+bool operator!=(Invalid) const { return _it != _end; }
+};
+/// Const iterator over the expression
+///The iterator iterates over the terms of the expression.
+///
+///\code
+///double s=0;
+///for(LpBase::Expr::ConstCoeffIt i(e);i!=INVALID;++i)
+///  s+=*i * primal(i);
+///\endcode
+class ConstCoeffIt {
+private:
+std::map<int, Value>::const_iterator _it, _end;
+public:
+/// Sets the iterator to the first term
+/// Sets the iterator to the first term of the expression.
+///
+ConstCoeffIt(const Expr& e)
+: _it(e.comps.begin()), _end(e.comps.end()){}
+/// Convert the iterator to the column of the term
+operator Col() const {
+return colFromId(_it->first);
+}
+/// Returns the coefficient of the term
+const Value& operator*() const { return _it->second; }
+/// Next term
+/// Assign the iterator to the next term.
+///
+ConstCoeffIt& operator++() { ++_it; return *this; }
+/// Equality operator
+bool operator==(Invalid) const { return _it == _end; }
+/// Inequality operator
+bool operator!=(Invalid) const { return _it != _end; }
+};
 };
 ///Linear constraint
 ///  e<=f
 ///  e==f
 ///  s<=e<=t
 ///  e>=t
 ///\endcode
-///\warning The validity of a constraint is checked only at run time, so
+///\warning The validity of a constraint is checked only at run
-///e.g. \ref addRow(<tt>x[1]\<=x[2]<=5</tt>) will compile, but will throw
+///time, so e.g. \ref addRow(<tt>x[1]\<=x[2]<=5</tt>) will
-///an assertion.
+///compile, but will fail an assertion.
 class Constr
 {
 public:
-typedef LpSolverBase::Expr Expr;
+typedef LpBase::Expr Expr;
 typedef Expr::Key Key;
 typedef Expr::Value Value;
 protected:
 Expr _expr;
 Value _lb,_ub;
 public:
 ///\e
 Constr() : _expr(), _lb(NaN), _ub(NaN) {}
 ///\e
-Constr(Value lb,const Expr &e,Value ub) :
+Constr(Value lb, const Expr &e, Value ub) :
 _expr(e), _lb(lb), _ub(ub) {}
-///\e
-Constr(const Expr &e,Value ub) :
-_expr(e), _lb(NaN), _ub(ub) {}
-///\e
-Constr(Value lb,const Expr &e) :
-_expr(e), _lb(lb), _ub(NaN) {}
-///\e
 Constr(const Expr &e) :
 _expr(e), _lb(NaN), _ub(NaN) {}
 ///\e
 void clear()
 {
 Value &upperBound() { return _ub; }
 ///The const version of \ref upperBound()
 const Value &upperBound() const { return _ub; }
 ///Is the constraint lower bounded?
 bool lowerBounded() const {
-return isFinite(_lb);
+return _lb != -INF && !std::isnan(_lb);
 }
 ///Is the constraint upper bounded?
 bool upperBounded() const {
-return isFinite(_ub);
+return _ub != INF && !std::isnan(_ub);
 }
 };
 ///Linear expression of rows
 ///thas is it strores a linear expression of the dual variables
 ///(\ref Row "Row"s).
 ///
 ///There are several ways to access and modify the contents of this
 ///container.
-///- Its it fully compatible with \c std::map<Row,double>, so for expamle
-///if \c e is an DualExpr and \c v
-///and \c w are of type \ref Row, then you can
-///read and modify the coefficients like
-///these.
 ///\code
 ///e[v]=5;
 ///e[v]+=12;
 ///e.erase(v);
 ///\endcode
 ///or you can also iterate through its elements.
 ///\code
 ///double s=0;
-///for(LpSolverBase::DualExpr::iterator i=e.begin();i!=e.end();++i)
+///for(LpBase::DualExpr::ConstCoeffIt i(e);i!=INVALID;++i)
-///  s+=i->second;
+///  s+=*i;
 ///\endcode
 ///(This code computes the sum of all coefficients).
 ///- Numbers (<tt>double</tt>'s)
 ///and variables (\ref Row "Row"s) directly convert to an
 ///\ref DualExpr and the usual linear operations are defined, so
 ///\code
 ///v+w
 ///2*v-3.12*(v-w/2)
 ///v*2.1+(3*v+(v*12+w)*3)/2
 ///\endcode
-///are valid \ref DualExpr "DualExpr"essions.
+///are valid \ref DualExpr dual expressions.
 ///The usual assignment operations are also defined.
 ///\code
 ///e=v+w;
 ///e+=2*v-3.12*(v-w/2);
 ///e*=3.4;
 ///e/=5;
 ///\endcode
 ///
 ///\sa Expr
-///
+class DualExpr {
-class DualExpr : public std::map<Row,Value>
+friend class LpBase;
-{
 public:
-typedef LpSolverBase::Row Key;
+/// The key type of the expression
-typedef LpSolverBase::Value Value;
+typedef LpBase::Row Key;
+/// The value type of the expression
+typedef LpBase::Value Value;
 protected:
-typedef std::map<Row,Value> Base;
+std::map<int, Value> comps;
 public:
-typedef True IsLinExpression;
+typedef True SolverExpr;
-///\e
+/// Default constructor
-DualExpr() : Base() { }
-///\e
+/// Construct an empty expression, the coefficients are
-DualExpr(const Key &v) {
+/// initialized to zero.
-Base::insert(std::make_pair(v, 1));
+DualExpr() {}
-}
+/// Construct an expression from a row
-///\e
-void set(const Key &v,const Value &c) {
+/// Construct an expression, which has a term with \c r dual
-Base::insert(std::make_pair(v, c));
+/// variable and 1.0 coefficient.
-}
+DualExpr(const Row &r) {
+typedef std::map<int, Value>::value_type pair_type;
-///Removes the components with zero coefficient.
+comps.insert(pair_type(id(r), 1));
-void simplify() {
+}
-for (Base::iterator i=Base::begin(); i!=Base::end();) {
+/// Returns the coefficient of the row
-Base::iterator j=i;
+Value operator[](const Row& r) const {
-++j;
+std::map<int, Value>::const_iterator it = comps.find(id(r));
-if ((*i).second==0) Base::erase(i);
+if (it != comps.end()) {
-i=j;
+return it->second;
+} else {
+return 0;
 }
 }
+/// Returns the coefficient of the row
-void simplify() const {
+Value& operator[](const Row& r) {
-const_cast<DualExpr*>(this)->simplify();
+return comps[id(r)];
 }
+/// Sets the coefficient of the row
-///Removes the coefficients closer to zero than \c tolerance.
+void set(const Row &r, const Value &v) {
-void simplify(double &tolerance) {
+if (v != 0.0) {
-for (Base::iterator i=Base::begin(); i!=Base::end();) {
+typedef std::map<int, Value>::value_type pair_type;
-Base::iterator j=i;
+comps.insert(pair_type(id(r), v));
-++j;
+} else {
-if (std::fabs((*i).second)<tolerance) Base::erase(i);
+comps.erase(id(r));
-i=j;
 }
+}
+/// \brief Removes the coefficients which's absolute value does
+/// not exceed \c epsilon.
+void simplify(Value epsilon = 0.0) {
+std::map<int, Value>::iterator it=comps.begin();
+while (it != comps.end()) {
+std::map<int, Value>::iterator jt=it;
+++jt;
+if (std::fabs((*it).second) <= epsilon) comps.erase(it);
+it=jt;
+}
+}
+void simplify(Value epsilon = 0.0) const {
+const_cast<DualExpr*>(this)->simplify(epsilon);
 }
 ///Sets all coefficients to 0.
 void clear() {
-Base::clear();
+comps.clear();
 }
+///Compound assignment
-///\e
 DualExpr &operator+=(const DualExpr &e) {
-for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
+for (std::map<int, Value>::const_iterator it=e.comps.begin();
-(*this)[j->first]+=j->second;
+it!=e.comps.end(); ++it)
+comps[it->first]+=it->second;
 return *this;
 }
-///\e
+///Compound assignment
 DualExpr &operator-=(const DualExpr &e) {
-for (Base::const_iterator j=e.begin(); j!=e.end(); ++j)
+for (std::map<int, Value>::const_iterator it=e.comps.begin();
-(*this)[j->first]-=j->second;
+it!=e.comps.end(); ++it)
+comps[it->first]-=it->second;
 return *this;
 }
-///\e
+///Multiply with a constant
-DualExpr &operator*=(const Value &c) {
+DualExpr &operator*=(const Value &v) {
-for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
+for (std::map<int, Value>::iterator it=comps.begin();
-j->second*=c;
+it!=comps.end(); ++it)
+it->second*=v;
 return *this;
 }
-///\e
+///Division with a constant
-DualExpr &operator/=(const Value &c) {
+DualExpr &operator/=(const Value &v) {
-for (Base::iterator j=Base::begin(); j!=Base::end(); ++j)
+for (std::map<int, Value>::iterator it=comps.begin();
-j->second/=c;
+it!=comps.end(); ++it)
+it->second/=v;
 return *this;
 }
+///Iterator over the expression
+///The iterator iterates over the terms of the expression.
+///
+///\code
+///double s=0;
+///for(LpBase::DualExpr::CoeffIt i(e);i!=INVALID;++i)
+///  s+= *i * dual(i);
+///\endcode
+class CoeffIt {
+private:
+std::map<int, Value>::iterator _it, _end;
+public:
+/// Sets the iterator to the first term
+/// Sets the iterator to the first term of the expression.
+///
+CoeffIt(DualExpr& e)
+: _it(e.comps.begin()), _end(e.comps.end()){}
+/// Convert the iterator to the row of the term
+operator Row() const {
+return rowFromId(_it->first);
+}
+/// Returns the coefficient of the term
+Value& operator*() { return _it->second; }
+/// Returns the coefficient of the term
+const Value& operator*() const { return _it->second; }
+/// Next term
+/// Assign the iterator to the next term.
+///
+CoeffIt& operator++() { ++_it; return *this; }
+/// Equality operator
+bool operator==(Invalid) const { return _it == _end; }
+/// Inequality operator
+bool operator!=(Invalid) const { return _it != _end; }
+};
+///Iterator over the expression
+///The iterator iterates over the terms of the expression.
+///
+///\code
+///double s=0;
+///for(LpBase::DualExpr::ConstCoeffIt i(e);i!=INVALID;++i)
+///  s+= *i * dual(i);
+///\endcode
+class ConstCoeffIt {
+private:
+std::map<int, Value>::const_iterator _it, _end;
+public:
+/// Sets the iterator to the first term
+/// Sets the iterator to the first term of the expression.
+///
+ConstCoeffIt(const DualExpr& e)
+: _it(e.comps.begin()), _end(e.comps.end()){}
+/// Convert the iterator to the row of the term
+operator Row() const {
+return rowFromId(_it->first);
+}
+/// Returns the coefficient of the term
+const Value& operator*() const { return _it->second; }
+/// Next term
+/// Assign the iterator to the next term.
+///
+ConstCoeffIt& operator++() { ++_it; return *this; }
+/// Equality operator
+bool operator==(Invalid) const { return _it == _end; }
+/// Inequality operator
+bool operator!=(Invalid) const { return _it != _end; }
+};
 };
-private:
+protected:
-template <typename _Expr>
+class InsertIterator {
-class MappedOutputIterator {
+private:
+std::map<int, Value>& _host;
+const _solver_bits::VarIndex& _index;
 public:
-typedef std::insert_iterator<_Expr> Base;
 typedef std::output_iterator_tag iterator_category;
 typedef void difference_type;
 typedef void value_type;
 typedef void reference;
 typedef void pointer;
-MappedOutputIterator(const Base& _base, const LpSolverBase& _lp)
+InsertIterator(std::map<int, Value>& host,
-: base(_base), lp(_lp) {}
+const _solver_bits::VarIndex& index)
+: _host(host), _index(index) {}
-MappedOutputIterator& operator*() {
+InsertIterator& operator=(const std::pair<int, Value>& value) {
+typedef std::map<int, Value>::value_type pair_type;
+_host.insert(pair_type(_index[value.first], value.second));
 return *this;
 }
-MappedOutputIterator& operator=(const std::pair<int, Value>& value) {
+InsertIterator& operator*() { return *this; }
-*base = std::make_pair(lp._item(value.first, typename _Expr::Key()),
+InsertIterator& operator++() { return *this; }
-value.second);
+InsertIterator operator++(int) { return *this; }
-return *this;
-}
+};
-MappedOutputIterator& operator++() {
+class ExprIterator {
-++base;
-return *this;
-}
-MappedOutputIterator operator++(int) {
-MappedOutputIterator tmp(*this);
-++base;
-return tmp;
-}
-bool operator==(const MappedOutputIterator& it) const {
-return base == it.base;
-}
-bool operator!=(const MappedOutputIterator& it) const {
-return base != it.base;
-}
 private:
-Base base;
+std::map<int, Value>::const_iterator _host_it;
-const LpSolverBase& lp;
+const _solver_bits::VarIndex& _index;
-};
-template <typename Expr>
-class MappedInputIterator {
 public:
-typedef typename Expr::const_iterator Base;
+typedef std::bidirectional_iterator_tag iterator_category;
+typedef std::ptrdiff_t difference_type;
-typedef typename Base::iterator_category iterator_category;
-typedef typename Base::difference_type difference_type;
 typedef const std::pair<int, Value> value_type;
 typedef value_type reference;
 class pointer {
 public:
 pointer(value_type& _value) : value(_value) {}
 value_type* operator->() { return &value; }
 private:
 value_type value;
 };
-MappedInputIterator(const Base& _base, const LpSolverBase& _lp)
+ExprIterator(const std::map<int, Value>::const_iterator& host_it,
-: base(_base), lp(_lp) {}
+const _solver_bits::VarIndex& index)
+: _host_it(host_it), _index(index) {}
 reference operator*() {
-return std::make_pair(lp._lpId(base->first), base->second);
+return std::make_pair(_index(_host_it->first), _host_it->second);
 }
 pointer operator->() {
 return pointer(operator*());
 }
-MappedInputIterator& operator++() {
+ExprIterator& operator++() { ++_host_it; return *this; }
-++base;
+ExprIterator operator++(int) {
-return *this;
+ExprIterator tmp(*this); ++_host_it; return tmp;
 }
-MappedInputIterator operator++(int) {
+ExprIterator& operator--() { --_host_it; return *this; }
-MappedInputIterator tmp(*this);
+ExprIterator operator--(int) {
-++base;
+ExprIterator tmp(*this); --_host_it; return tmp;
-return tmp;
+}
-}
+bool operator==(const ExprIterator& it) const {
-bool operator==(const MappedInputIterator& it) const {
+return _host_it == it._host_it;
-return base == it.base;
+}
-}
+bool operator!=(const ExprIterator& it) const {
-bool operator!=(const MappedInputIterator& it) const {
+return _host_it != it._host_it;
-return base != it.base;
+}
-}
-private:
-Base base;
-const LpSolverBase& lp;
 };
 protected:
-/// STL compatible iterator for lp col
-typedef MappedInputIterator<Expr> ConstRowIterator;
-/// STL compatible iterator for lp row
-typedef MappedInputIterator<DualExpr> ConstColIterator;
-/// STL compatible iterator for lp col
-typedef MappedOutputIterator<Expr> RowIterator;
-/// STL compatible iterator for lp row
-typedef MappedOutputIterator<DualExpr> ColIterator;
 //Abstract virtual functions
-virtual LpSolverBase* _newLp() = 0;
+virtual LpBase* _newSolver() const = 0;
-virtual LpSolverBase* _copyLp(){
+virtual LpBase* _cloneSolver() const = 0;
-LpSolverBase* newlp = _newLp();
+virtual int _addColId(int col) { return cols.addIndex(col); }
-std::map<Col, Col> ref;
+virtual int _addRowId(int row) { return rows.addIndex(row); }
-for (LpSolverBase::ColIt it(*this); it != INVALID; ++it) {
-Col ccol = newlp->addCol();
+virtual void _eraseColId(int col) { cols.eraseIndex(col); }
-ref[it] = ccol;
+virtual void _eraseRowId(int row) { rows.eraseIndex(row); }
-newlp->colName(ccol, colName(it));
-newlp->colLowerBound(ccol, colLowerBound(it));
-newlp->colUpperBound(ccol, colUpperBound(it));
-}
-for (LpSolverBase::RowIt it(*this); it != INVALID; ++it) {
-Expr e = row(it), ce;
-for (Expr::iterator jt = e.begin(); jt != e.end(); ++jt) {
-ce[ref[jt->first]] = jt->second;
-}
-ce += e.constComp();
-Row r = newlp->addRow(ce);
-double lower, upper;
-getRowBounds(it, lower, upper);
-newlp->rowBounds(r, lower, upper);
-}
-return newlp;
-};
 virtual int _addCol() = 0;
 virtual int _addRow() = 0;
 virtual void _eraseCol(int col) = 0;
 virtual void _eraseRow(int row) = 0;
-virtual void _getColName(int col, std::string & name) const = 0;
+virtual void _getColName(int col, std::string& name) const = 0;
-virtual void _setColName(int col, const std::string & name) = 0;
+virtual void _setColName(int col, const std::string& name) = 0;
 virtual int _colByName(const std::string& name) const = 0;
-virtual void _setRowCoeffs(int i, ConstRowIterator b,
+virtual void _getRowName(int row, std::string& name) const = 0;
-ConstRowIterator e) = 0;
+virtual void _setRowName(int row, const std::string& name) = 0;
-virtual void _getRowCoeffs(int i, RowIterator b) const = 0;
+virtual int _rowByName(const std::string& name) const = 0;
-virtual void _setColCoeffs(int i, ConstColIterator b,
-ConstColIterator e) = 0;
+virtual void _setRowCoeffs(int i, ExprIterator b, ExprIterator e) = 0;
-virtual void _getColCoeffs(int i, ColIterator b) const = 0;
+virtual void _getRowCoeffs(int i, InsertIterator b) const = 0;
+virtual void _setColCoeffs(int i, ExprIterator b, ExprIterator e) = 0;
+virtual void _getColCoeffs(int i, InsertIterator b) const = 0;
 virtual void _setCoeff(int row, int col, Value value) = 0;
 virtual Value _getCoeff(int row, int col) const = 0;
 virtual void _setColLowerBound(int i, Value value) = 0;
 virtual Value _getColLowerBound(int i) const = 0;
 virtual void _setColUpperBound(int i, Value value) = 0;
 virtual Value _getColUpperBound(int i) const = 0;
-virtual void _setRowBounds(int i, Value lower, Value upper) = 0;
-virtual void _getRowBounds(int i, Value &lower, Value &upper) const = 0;
+virtual void _setRowLowerBound(int i, Value value) = 0;
+virtual Value _getRowLowerBound(int i) const = 0;
+virtual void _setRowUpperBound(int i, Value value) = 0;
+virtual Value _getRowUpperBound(int i) const = 0;
+virtual void _setObjCoeffs(ExprIterator b, ExprIterator e) = 0;
+virtual void _getObjCoeffs(InsertIterator b) const = 0;
 virtual void _setObjCoeff(int i, Value obj_coef) = 0;
 virtual Value _getObjCoeff(int i) const = 0;
-virtual void _clearObj()=0;
+virtual void _setSense(Sense) = 0;
-virtual SolveExitStatus _solve() = 0;
+virtual Sense _getSense() const = 0;
-virtual Value _getPrimal(int i) const = 0;
-virtual Value _getDual(int i) const = 0;
+virtual void _clear() = 0;
-virtual Value _getPrimalValue() const = 0;
-virtual bool _isBasicCol(int i) const = 0;
+virtual const char* _solverName() const = 0;
-virtual SolutionStatus _getPrimalStatus() const = 0;
-virtual SolutionStatus _getDualStatus() const = 0;
-virtual ProblemTypes _getProblemType() const = 0;
-virtual void _setMax() = 0;
-virtual void _setMin() = 0;
-virtual bool _isMax() const = 0;
 //Own protected stuff
 //Constant component of the objective function
 Value obj_const_comp;
+LpBase() : rows(), cols(), obj_const_comp(0) {}
 public:
-///\e
+/// Virtual destructor
-LpSolverBase() : obj_const_comp(0) {}
+virtual ~LpBase() {}
-///\e
-virtual ~LpSolverBase() {}
 ///Creates a new LP problem
-LpSolverBase* newLp() {return _newLp();}
+LpBase* newSolver() {return _newSolver();}
 ///Makes a copy of the LP problem
-LpSolverBase* copyLp() {return _copyLp();}
+LpBase* cloneSolver() {return _cloneSolver();}
+///Gives back the name of the solver.
+const char* solverName() const {return _solverName();}
 ///\name Build up and modify the LP
 ///@{
 ///Add a new empty column (i.e a new variable) to the LP
-Col addCol() { Col c; _addCol(); c.id = cols.addId(); return c;}
+Col addCol() { Col c; c._id = _addColId(_addCol()); return c;}
-///\brief Adds several new columns
+///\brief Adds several new columns (i.e variables) at once
-///(i.e a variables) at once
+///
-///
+///This magic function takes a container as its argument and fills
-///This magic function takes a container as its argument
+///its elements with new columns (i.e. variables)
-///and fills its elements
-///with new columns (i.e. variables)
 ///\param t can be
 ///- a standard STL compatible iterable container with
-///\ref Col as its \c values_type
+///\ref Col as its \c values_type like
-///like
 ///\code
-///std::vector<LpSolverBase::Col>
+///std::vector<LpBase::Col>
-///std::list<LpSolverBase::Col>
+///std::list<LpBase::Col>
 ///\endcode
 ///- a standard STL compatible iterable container with
-///\ref Col as its \c mapped_type
+///\ref Col as its \c mapped_type like
-///like
 ///\code
-///std::map<AnyType,LpSolverBase::Col>
+///std::map<AnyType,LpBase::Col>
 ///\endcode
 ///- an iterable lemon \ref concepts::WriteMap "write map" like
 ///\code
-///ListGraph::NodeMap<LpSolverBase::Col>
+///ListGraph::NodeMap<LpBase::Col>
-///ListGraph::EdgeMap<LpSolverBase::Col>
+///ListGraph::ArcMap<LpBase::Col>
 ///\endcode
 ///\return The number of the created column.
 #ifdef DOXYGEN
 template<class T>
 int addColSet(T &t) { return 0;}
 #else
 template<class T>
-typename enable_if<typename T::value_type::LpSolverCol,int>::type
+typename enable_if<typename T::value_type::LpCol,int>::type
 addColSet(T &t,dummy<0> = 0) {
 int s=0;
 for(typename T::iterator i=t.begin();i!=t.end();++i) {*i=addCol();s++;}
 return s;
 }
 template<class T>
-typename enable_if<typename T::value_type::second_type::LpSolverCol,
+typename enable_if<typename T::value_type::second_type::LpCol,
 int>::type
 addColSet(T &t,dummy<1> = 1) {
 int s=0;
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 i->second=addCol();
 s++;
 }
 return s;
 }
 template<class T>
-typename enable_if<typename T::MapIt::Value::LpSolverCol,
+typename enable_if<typename T::MapIt::Value::LpCol,
 int>::type
 addColSet(T &t,dummy<2> = 2) {
 int s=0;
 for(typename T::MapIt i(t); i!=INVALID; ++i)
 {
 ///Set a column (i.e a dual constraint) of the LP
 ///\param c is the column to be modified
 ///\param e is a dual linear expression (see \ref DualExpr)
 ///a better one.
-void col(Col c,const DualExpr &e) {
+void col(Col c, const DualExpr &e) {
 e.simplify();
-_setColCoeffs(_lpId(c), ConstColIterator(e.begin(), *this),
+_setColCoeffs(cols(id(c)), ExprIterator(e.comps.begin(), cols),
-ConstColIterator(e.end(), *this));
+ExprIterator(e.comps.end(), cols));
 }
 ///Get a column (i.e a dual constraint) of the LP
-///\param r is the column to get
+///\param c is the column to get
 ///\return the dual expression associated to the column
 DualExpr col(Col c) const {
 DualExpr e;
-_getColCoeffs(_lpId(c), ColIterator(std::inserter(e, e.end()), *this));
+_getColCoeffs(cols(id(c)), InsertIterator(e.comps, rows));
 return e;
 }
 ///Add a new column to the LP
 ///\param e is a dual linear expression (see \ref DualExpr)
-///\param obj is the corresponding component of the objective
+///\param o is the corresponding component of the objective
 ///function. It is 0 by default.
 ///\return The created column.
 Col addCol(const DualExpr &e, Value o = 0) {
 Col c=addCol();
 col(c,e);
 ///Add a new empty row (i.e a new constraint) to the LP
 ///This function adds a new empty row (i.e a new constraint) to the LP.
 ///\return The created row
-Row addRow() { Row r; _addRow(); r.id = rows.addId(); return r;}
+Row addRow() { Row r; r._id = _addRowId(_addRow()); return r;}
-///\brief Add several new rows
+///\brief Add several new rows (i.e constraints) at once
-///(i.e a constraints) at once
+///
-///
+///This magic function takes a container as its argument and fills
-///This magic function takes a container as its argument
+///its elements with new row (i.e. variables)
-///and fills its elements
-///with new row (i.e. variables)
 ///\param t can be
 ///- a standard STL compatible iterable container with
-///\ref Row as its \c values_type
+///\ref Row as its \c values_type like
-///like
 ///\code
-///std::vector<LpSolverBase::Row>
+///std::vector<LpBase::Row>
-///std::list<LpSolverBase::Row>
+///std::list<LpBase::Row>
 ///\endcode
 ///- a standard STL compatible iterable container with
-///\ref Row as its \c mapped_type
+///\ref Row as its \c mapped_type like
-///like
 ///\code
-///std::map<AnyType,LpSolverBase::Row>
+///std::map<AnyType,LpBase::Row>
 ///\endcode
 ///- an iterable lemon \ref concepts::WriteMap "write map" like
 ///\code
-///ListGraph::NodeMap<LpSolverBase::Row>
+///ListGraph::NodeMap<LpBase::Row>
-///ListGraph::EdgeMap<LpSolverBase::Row>
+///ListGraph::ArcMap<LpBase::Row>
 ///\endcode
 ///\return The number of rows created.
 #ifdef DOXYGEN
 template<class T>
 int addRowSet(T &t) { return 0;}
 #else
 template<class T>
-typename enable_if<typename T::value_type::LpSolverRow,int>::type
+typename enable_if<typename T::value_type::LpRow,int>::type
-addRowSet(T &t,dummy<0> = 0) {
+addRowSet(T &t, dummy<0> = 0) {
 int s=0;
 for(typename T::iterator i=t.begin();i!=t.end();++i) {*i=addRow();s++;}
 return s;
 }
 template<class T>
-typename enable_if<typename T::value_type::second_type::LpSolverRow,
+typename enable_if<typename T::value_type::second_type::LpRow, int>::type
-int>::type
+addRowSet(T &t, dummy<1> = 1) {
-addRowSet(T &t,dummy<1> = 1) {
 int s=0;
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 i->second=addRow();
 s++;
 }
 return s;
 }
 template<class T>
-typename enable_if<typename T::MapIt::Value::LpSolverRow,
+typename enable_if<typename T::MapIt::Value::LpRow, int>::type
-int>::type
+addRowSet(T &t, dummy<2> = 2) {
-addRowSet(T &t,dummy<2> = 2) {
 int s=0;
 for(typename T::MapIt i(t); i!=INVALID; ++i)
 {
 i.set(addRow());
 s++;
 ///\param r is the row to be modified
 ///\param l is lower bound (-\ref INF means no bound)
 ///\param e is a linear expression (see \ref Expr)
 ///\param u is the upper bound (\ref INF means no bound)
-///\bug This is a temporary function. The interface will change to
-///a better one.
-///\todo Option to control whether a constraint with a single variable is
-///added or not.
 void row(Row r, Value l, const Expr &e, Value u) {
 e.simplify();
-_setRowCoeffs(_lpId(r), ConstRowIterator(e.begin(), *this),
+_setRowCoeffs(rows(id(r)), ExprIterator(e.comps.begin(), cols),
-ConstRowIterator(e.end(), *this));
+ExprIterator(e.comps.end(), cols));
-_setRowBounds(_lpId(r),l-e.constComp(),u-e.constComp());
+_setRowLowerBound(rows(id(r)),l - *e);
+_setRowUpperBound(rows(id(r)),u - *e);
 }
 ///Set a row (i.e a constraint) of the LP
 ///\param r is the row to be modified
 ///\param r is the row to get
 ///\return the expression associated to the row
 Expr row(Row r) const {
 Expr e;
-_getRowCoeffs(_lpId(r), RowIterator(std::inserter(e, e.end()), *this));
+_getRowCoeffs(rows(id(r)), InsertIterator(e.comps, cols));
 return e;
 }
 ///Add a new row (i.e a new constraint) to the LP
 ///\param l is the lower bound (-\ref INF means no bound)
 ///\param e is a linear expression (see \ref Expr)
 ///\param u is the upper bound (\ref INF means no bound)
 ///\return The created row.
-///\bug This is a temporary function. The interface will change to
-///a better one.
 Row addRow(Value l,const Expr &e, Value u) {
 Row r=addRow();
 row(r,l,e,u);
 return r;
 }
 Row addRow(const Constr &c) {
 Row r=addRow();
 row(r,c);
 return r;
 }
-///Erase a coloumn (i.e a variable) from the LP
+///Erase a column (i.e a variable) from the LP
-///\param c is the coloumn to be deleted
+///\param c is the column to be deleted
-///\todo Please check this
+void erase(Col c) {
-void eraseCol(Col c) {
+_eraseCol(cols(id(c)));
-_eraseCol(_lpId(c));
+_eraseColId(cols(id(c)));
-cols.eraseId(c.id);
+}
-}
+///Erase a row (i.e a constraint) from the LP
-///Erase a  row (i.e a constraint) from the LP
 ///\param r is the row to be deleted
-///\todo Please check this
+void erase(Row r) {
-void eraseRow(Row r) {
+_eraseRow(rows(id(r)));
-_eraseRow(_lpId(r));
+_eraseRowId(rows(id(r)));
-rows.eraseId(r.id);
 }
 /// Get the name of a column
-///\param c is the coresponding coloumn
+///\param c is the coresponding column
 ///\return The name of the colunm
 std::string colName(Col c) const {
 std::string name;
-_getColName(_lpId(c), name);
+_getColName(cols(id(c)), name);
 return name;
 }
 /// Set the name of a column
-///\param c is the coresponding coloumn
+///\param c is the coresponding column
 ///\param name The name to be given
 void colName(Col c, const std::string& name) {
-_setColName(_lpId(c), name);
+_setColName(cols(id(c)), name);
 }
 /// Get the column by its name
 ///\param name The name of the column
 ///\return the proper column or \c INVALID
 Col colByName(const std::string& name) const {
 int k = _colByName(name);
-return k != -1 ? Col(cols.fixId(k)) : Col(INVALID);
+return k != -1 ? Col(cols[k]) : Col(INVALID);
+}
+/// Get the name of a row
+///\param r is the coresponding row
+///\return The name of the row
+std::string rowName(Row r) const {
+std::string name;
+_getRowName(rows(id(r)), name);
+return name;
+}
+/// Set the name of a row
+///\param r is the coresponding row
+///\param name The name to be given
+void rowName(Row r, const std::string& name) {
+_setRowName(rows(id(r)), name);
+}
+/// Get the row by its name
+///\param name The name of the row
+///\return the proper row or \c INVALID
+Row rowByName(const std::string& name) const {
+int k = _rowByName(name);
+return k != -1 ? Row(rows[k]) : Row(INVALID);
 }
 /// Set an element of the coefficient matrix of the LP
 ///\param r is the row of the element to be modified
-///\param c is the coloumn of the element to be modified
+///\param c is the column of the element to be modified
 ///\param val is the new value of the coefficient
 void coeff(Row r, Col c, Value val) {
-_setCoeff(_lpId(r),_lpId(c), val);
+_setCoeff(rows(id(r)),cols(id(c)), val);
 }
 /// Get an element of the coefficient matrix of the LP
-///\param r is the row of the element in question
+///\param r is the row of the element
-///\param c is the coloumn of the element in question
+///\param c is the column of the element
 ///\return the corresponding coefficient
 Value coeff(Row r, Col c) const {
-return _getCoeff(_lpId(r),_lpId(c));
+return _getCoeff(rows(id(r)),cols(id(c)));
 }
 /// Set the lower bound of a column (i.e a variable)
 /// The lower bound of a variable (column) has to be given by an
 /// extended number of type Value, i.e. a finite number of type
 /// Value or -\ref INF.
 void colLowerBound(Col c, Value value) {
-_setColLowerBound(_lpId(c),value);
+_setColLowerBound(cols(id(c)),value);
 }
 /// Get the lower bound of a column (i.e a variable)
-/// This function returns the lower bound for column (variable) \t c
+/// This function returns the lower bound for column (variable) \c c
 /// (this might be -\ref INF as well).
-///\return The lower bound for coloumn \t c
+///\return The lower bound for column \c c
 Value colLowerBound(Col c) const {
-return _getColLowerBound(_lpId(c));
+return _getColLowerBound(cols(id(c)));
 }
 ///\brief Set the lower bound of  several columns
-///(i.e a variables) at once
+///(i.e variables) at once
 ///
 ///This magic function takes a container as its argument
 ///and applies the function on all of its elements.
-/// The lower bound of a variable (column) has to be given by an
+///The lower bound of a variable (column) has to be given by an
-/// extended number of type Value, i.e. a finite number of type
+///extended number of type Value, i.e. a finite number of type
-/// Value or -\ref INF.
+///Value or -\ref INF.
 #ifdef DOXYGEN
 template<class T>
 void colLowerBound(T &t, Value value) { return 0;}
 #else
 template<class T>
-typename enable_if<typename T::value_type::LpSolverCol,void>::type
+typename enable_if<typename T::value_type::LpCol,void>::type
 colLowerBound(T &t, Value value,dummy<0> = 0) {
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 colLowerBound(*i, value);
 }
 }
 template<class T>
-typename enable_if<typename T::value_type::second_type::LpSolverCol,
+typename enable_if<typename T::value_type::second_type::LpCol,
 void>::type
 colLowerBound(T &t, Value value,dummy<1> = 1) {
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 colLowerBound(i->second, value);
 }
 }
 template<class T>
-typename enable_if<typename T::MapIt::Value::LpSolverCol,
+typename enable_if<typename T::MapIt::Value::LpCol,
 void>::type
 colLowerBound(T &t, Value value,dummy<2> = 2) {
 for(typename T::MapIt i(t); i!=INVALID; ++i){
 colLowerBound(*i, value);
 }
 /// The upper bound of a variable (column) has to be given by an
 /// extended number of type Value, i.e. a finite number of type
 /// Value or \ref INF.
 void colUpperBound(Col c, Value value) {
-_setColUpperBound(_lpId(c),value);
+_setColUpperBound(cols(id(c)),value);
 };
 /// Get the upper bound of a column (i.e a variable)
-/// This function returns the upper bound for column (variable) \t c
+/// This function returns the upper bound for column (variable) \c c
 /// (this might be \ref INF as well).
-///\return The upper bound for coloumn \t c
+/// \return The upper bound for column \c c
 Value colUpperBound(Col c) const {
-return _getColUpperBound(_lpId(c));
+return _getColUpperBound(cols(id(c)));
 }
 ///\brief Set the upper bound of  several columns
-///(i.e a variables) at once
+///(i.e variables) at once
 ///
 ///This magic function takes a container as its argument
 ///and applies the function on all of its elements.
-/// The upper bound of a variable (column) has to be given by an
+///The upper bound of a variable (column) has to be given by an
-/// extended number of type Value, i.e. a finite number of type
+///extended number of type Value, i.e. a finite number of type
-/// Value or \ref INF.
+///Value or \ref INF.
 #ifdef DOXYGEN
 template<class T>
 void colUpperBound(T &t, Value value) { return 0;}
 #else
 template<class T>
-typename enable_if<typename T::value_type::LpSolverCol,void>::type
+typename enable_if<typename T::value_type::LpCol,void>::type
 colUpperBound(T &t, Value value,dummy<0> = 0) {
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 colUpperBound(*i, value);
 }
 }
 template<class T>
-typename enable_if<typename T::value_type::second_type::LpSolverCol,
+typename enable_if<typename T::value_type::second_type::LpCol,
 void>::type
 colUpperBound(T &t, Value value,dummy<1> = 1) {
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 colUpperBound(i->second, value);
 }
 }
 template<class T>
-typename enable_if<typename T::MapIt::Value::LpSolverCol,
+typename enable_if<typename T::MapIt::Value::LpCol,
 void>::type
 colUpperBound(T &t, Value value,dummy<2> = 2) {
 for(typename T::MapIt i(t); i!=INVALID; ++i){
 colUpperBound(*i, value);
 }
 /// The lower and the upper bounds of
 /// a variable (column) have to be given by an
 /// extended number of type Value, i.e. a finite number of type
 /// Value, -\ref INF or \ref INF.
 void colBounds(Col c, Value lower, Value upper) {
-_setColLowerBound(_lpId(c),lower);
+_setColLowerBound(cols(id(c)),lower);
-_setColUpperBound(_lpId(c),upper);
+_setColUpperBound(cols(id(c)),upper);
 }
 ///\brief Set the lower and the upper bound of several columns
-///(i.e a variables) at once
+///(i.e variables) at once
 ///
 ///This magic function takes a container as its argument
 ///and applies the function on all of its elements.
 /// The lower and the upper bounds of
 /// a variable (column) have to be given by an
 #ifdef DOXYGEN
 template<class T>
 void colBounds(T &t, Value lower, Value upper) { return 0;}
 #else
 template<class T>
-typename enable_if<typename T::value_type::LpSolverCol,void>::type
+typename enable_if<typename T::value_type::LpCol,void>::type
 colBounds(T &t, Value lower, Value upper,dummy<0> = 0) {
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 colBounds(*i, lower, upper);
 }
 }
 template<class T>
-typename enable_if<typename T::value_type::second_type::LpSolverCol,
+typename enable_if<typename T::value_type::second_type::LpCol, void>::type
-void>::type
 colBounds(T &t, Value lower, Value upper,dummy<1> = 1) {
 for(typename T::iterator i=t.begin();i!=t.end();++i) {
 colBounds(i->second, lower, upper);
 }
 }
 template<class T>
-typename enable_if<typename T::MapIt::Value::LpSolverCol,
+typename enable_if<typename T::MapIt::Value::LpCol, void>::type
-void>::type
 colBounds(T &t, Value lower, Value upper,dummy<2> = 2) {
 for(typename T::MapIt i(t); i!=INVALID; ++i){
 colBounds(*i, lower, upper);
 }
 }
 #endif
+/// Set the lower bound of a row (i.e a constraint)
-/// Set the lower and the upper bounds of a row (i.e a constraint)
+/// The lower bound of a constraint (row) has to be given by an
-/// The lower and the upper bound of a constraint (row) have to be
+/// extended number of type Value, i.e. a finite number of type
-/// given by an extended number of type Value, i.e. a finite
+/// Value or -\ref INF.
-/// number of type Value, -\ref INF or \ref INF. There is no
+void rowLowerBound(Row r, Value value) {
-/// separate function for the lower and the upper bound because
+_setRowLowerBound(rows(id(r)),value);
-/// that would have been hard to implement for CPLEX.
+}
-void rowBounds(Row c, Value lower, Value upper) {
-_setRowBounds(_lpId(c),lower, upper);
+/// Get the lower bound of a row (i.e a constraint)
-}
+/// This function returns the lower bound for row (constraint) \c c
-/// Get the lower and the upper bounds of a row (i.e a constraint)
+/// (this might be -\ref INF as well).
+///\return The lower bound for row \c r
-/// The lower and the upper bound of
+Value rowLowerBound(Row r) const {
-/// a constraint (row) are
+return _getRowLowerBound(rows(id(r)));
-/// extended numbers of type Value, i.e.  finite numbers of type
+}
-/// Value, -\ref INF or \ref INF.
-/// \todo There is no separate function for the
+/// Set the upper bound of a row (i.e a constraint)
-/// lower and the upper bound because we had problems with the
-/// implementation of the setting functions for CPLEX:
+/// The upper bound of a constraint (row) has to be given by an
-/// check out whether this can be done for these functions.
+/// extended number of type Value, i.e. a finite number of type
-void getRowBounds(Row c, Value &lower, Value &upper) const {
+/// Value or -\ref INF.
-_getRowBounds(_lpId(c),lower, upper);
+void rowUpperBound(Row r, Value value) {
+_setRowUpperBound(rows(id(r)),value);
+}
+/// Get the upper bound of a row (i.e a constraint)
+/// This function returns the upper bound for row (constraint) \c c
+/// (this might be -\ref INF as well).
+///\return The upper bound for row \c r
+Value rowUpperBound(Row r) const {
+return _getRowUpperBound(rows(id(r)));
 }
 ///Set an element of the objective function
-void objCoeff(Col c, Value v) {_setObjCoeff(_lpId(c),v); };
+void objCoeff(Col c, Value v) {_setObjCoeff(cols(id(c)),v); };
 ///Get an element of the objective function
-Value objCoeff(Col c) const { return _getObjCoeff(_lpId(c)); };
+Value objCoeff(Col c) const { return _getObjCoeff(cols(id(c))); };
 ///Set the objective function
 ///\param e is a linear expression of type \ref Expr.
-void obj(Expr e) {
+///
-_clearObj();
+void obj(const Expr& e) {
-for (Expr::iterator i=e.begin(); i!=e.end(); ++i)
+_setObjCoeffs(ExprIterator(e.comps.begin(), cols),
-objCoeff((*i).first,(*i).second);
+ExprIterator(e.comps.end(), cols));
-obj_const_comp=e.constComp();
+obj_const_comp = *e;
 }
 ///Get the objective function
-///\return the objective function as a linear expression of type \ref Expr.
+///\return the objective function as a linear expression of type
+///Expr.
 Expr obj() const {
 Expr e;
-for (ColIt it(*this); it != INVALID; ++it) {
+_getObjCoeffs(InsertIterator(e.comps, cols));
-double c = objCoeff(it);
+*e = obj_const_comp;
-if (c != 0.0) {
-e.insert(std::make_pair(it, c));
-}
-}
 return e;
 }
-///Maximize
+///Set the direction of optimization
-void max() { _setMax(); }
+void sense(Sense sense) { _setSense(sense); }
-///Minimize
-void min() { _setMin(); }
+///Query the direction of the optimization
+Sense sense() const {return _getSense(); }
-///Query function: is this a maximization problem?
-bool isMax() const {return _isMax(); }
+///Set the sense to maximization
+void max() { _setSense(MAX); }
-///Query function: is this a minimization problem?
-bool isMin() const {return !isMax(); }
+///Set the sense to maximization
+void min() { _setSense(MIN); }
+///Clears the problem
+void clear() { _clear(); }
 ///@}
+};
+/// Addition
+///\relates LpBase::Expr
+///
+inline LpBase::Expr operator+(const LpBase::Expr &a, const LpBase::Expr &b) {
+LpBase::Expr tmp(a);
+tmp+=b;
+return tmp;
+}
+///Substraction
+///\relates LpBase::Expr
+///
+inline LpBase::Expr operator-(const LpBase::Expr &a, const LpBase::Expr &b) {
+LpBase::Expr tmp(a);
+tmp-=b;
+return tmp;
+}
+///Multiply with constant
+///\relates LpBase::Expr
+///
+inline LpBase::Expr operator*(const LpBase::Expr &a, const LpBase::Value &b) {
+LpBase::Expr tmp(a);
+tmp*=b;
+return tmp;
+}
+///Multiply with constant
+///\relates LpBase::Expr
+///
+inline LpBase::Expr operator*(const LpBase::Value &a, const LpBase::Expr &b) {
+LpBase::Expr tmp(b);
+tmp*=a;
+return tmp;
+}
+///Divide with constant
+///\relates LpBase::Expr
+///
+inline LpBase::Expr operator/(const LpBase::Expr &a, const LpBase::Value &b) {
+LpBase::Expr tmp(a);
+tmp/=b;
+return tmp;
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator<=(const LpBase::Expr &e,
+const LpBase::Expr &f) {
+return LpBase::Constr(0, f - e, LpBase::INF);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator<=(const LpBase::Value &e,
+const LpBase::Expr &f) {
+return LpBase::Constr(e, f, LpBase::NaN);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator<=(const LpBase::Expr &e,
+const LpBase::Value &f) {
+return LpBase::Constr(- LpBase::INF, e, f);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator>=(const LpBase::Expr &e,
+const LpBase::Expr &f) {
+return LpBase::Constr(0, e - f, LpBase::INF);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator>=(const LpBase::Value &e,
+const LpBase::Expr &f) {
+return LpBase::Constr(LpBase::NaN, f, e);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator>=(const LpBase::Expr &e,
+const LpBase::Value &f) {
+return LpBase::Constr(f, e, LpBase::INF);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator==(const LpBase::Expr &e,
+const LpBase::Value &f) {
+return LpBase::Constr(f, e, f);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator==(const LpBase::Expr &e,
+const LpBase::Expr &f) {
+return LpBase::Constr(0, f - e, 0);
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator<=(const LpBase::Value &n,
+const LpBase::Constr &c) {
+LpBase::Constr tmp(c);
+LEMON_ASSERT(std::isnan(tmp.lowerBound()), "Wrong LP constraint");
+tmp.lowerBound()=n;
+return tmp;
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator<=(const LpBase::Constr &c,
+const LpBase::Value &n)
+{
+LpBase::Constr tmp(c);
+LEMON_ASSERT(std::isnan(tmp.upperBound()), "Wrong LP constraint");
+tmp.upperBound()=n;
+return tmp;
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator>=(const LpBase::Value &n,
+const LpBase::Constr &c) {
+LpBase::Constr tmp(c);
+LEMON_ASSERT(std::isnan(tmp.upperBound()), "Wrong LP constraint");
+tmp.upperBound()=n;
+return tmp;
+}
+///Create constraint
+///\relates LpBase::Constr
+///
+inline LpBase::Constr operator>=(const LpBase::Constr &c,
+const LpBase::Value &n)
+{
+LpBase::Constr tmp(c);
+LEMON_ASSERT(std::isnan(tmp.lowerBound()), "Wrong LP constraint");
+tmp.lowerBound()=n;
+return tmp;
+}
+///Addition
+///\relates LpBase::DualExpr
+///
+inline LpBase::DualExpr operator+(const LpBase::DualExpr &a,
+const LpBase::DualExpr &b) {
+LpBase::DualExpr tmp(a);
+tmp+=b;
+return tmp;
+}
+///Substraction
+///\relates LpBase::DualExpr
+///
+inline LpBase::DualExpr operator-(const LpBase::DualExpr &a,
+const LpBase::DualExpr &b) {
+LpBase::DualExpr tmp(a);
+tmp-=b;
+return tmp;
+}
+///Multiply with constant
+///\relates LpBase::DualExpr
+///
+inline LpBase::DualExpr operator*(const LpBase::DualExpr &a,
+const LpBase::Value &b) {
+LpBase::DualExpr tmp(a);
+tmp*=b;
+return tmp;
+}
+///Multiply with constant
+///\relates LpBase::DualExpr
+///
+inline LpBase::DualExpr operator*(const LpBase::Value &a,
+const LpBase::DualExpr &b) {
+LpBase::DualExpr tmp(b);
+tmp*=a;
+return tmp;
+}
+///Divide with constant
+///\relates LpBase::DualExpr
+///
+inline LpBase::DualExpr operator/(const LpBase::DualExpr &a,
+const LpBase::Value &b) {
+LpBase::DualExpr tmp(a);
+tmp/=b;
+return tmp;
+}
+/// \ingroup lp_group
+///
+/// \brief Common base class for LP solvers
+///
+/// This class is an abstract base class for LP solvers. This class
+/// provides a full interface for set and modify an LP problem,
+/// solve it and retrieve the solution. You can use one of the
+/// descendants as a concrete implementation, or the \c Lp
+/// default LP solver. However, if you would like to handle LP
+/// solvers as reference or pointer in a generic way, you can use
+/// this class directly.
+class LpSolver : virtual public LpBase {
+public:
+/// The problem types for primal and dual problems
+enum ProblemType {
+///Feasible solution hasn't been found (but may exist).
+UNDEFINED = 0,
+///The problem has no feasible solution
+INFEASIBLE = 1,
+///Feasible solution found
+FEASIBLE = 2,
+///Optimal solution exists and found
+OPTIMAL = 3,
+///The cost function is unbounded
+UNBOUNDED = 4
+};
+///The basis status of variables
+enum VarStatus {
+/// The variable is in the basis
+BASIC,
+/// The variable is free, but not basic
+FREE,
+/// The variable has active lower bound
+LOWER,
+/// The variable has active upper bound
+UPPER,
+/// The variable is non-basic and fixed
+FIXED
+};
+protected:
+virtual SolveExitStatus _solve() = 0;
+virtual Value _getPrimal(int i) const = 0;
+virtual Value _getDual(int i) const = 0;
+virtual Value _getPrimalRay(int i) const = 0;
+virtual Value _getDualRay(int i) const = 0;
+virtual Value _getPrimalValue() const = 0;
+virtual VarStatus _getColStatus(int i) const = 0;
+virtual VarStatus _getRowStatus(int i) const = 0;
+virtual ProblemType _getPrimalType() const = 0;
+virtual ProblemType _getDualType() const = 0;
+public:
 ///\name Solve the LP
 ///@{
 ///\e Solve the LP problem at hand
 ///
 ///\return The result of the optimization procedure. Possible
 ///values and their meanings can be found in the documentation of
 ///\ref SolveExitStatus.
-///
-///\todo Which method is used to solve the problem
 SolveExitStatus solve() { return _solve(); }
 ///@}
 ///\name Obtain the solution
 ///@{
-/// The status of the primal problem (the original LP problem)
+/// The type of the primal problem
-SolutionStatus primalStatus() const {
+ProblemType primalType() const {
-return _getPrimalStatus();
+return _getPrimalType();
 }
-/// The status of the dual (of the original LP) problem
+/// The type of the dual problem
-SolutionStatus dualStatus() const {
+ProblemType dualType() const {
-return _getDualStatus();
+return _getDualType();
 }
-///The type of the original LP problem
+/// Return the primal value of the column
-ProblemTypes problemType() const {
-return _getProblemType();
+/// Return the primal value of the column.
-}
+/// \pre The problem is solved.
+Value primal(Col c) const { return _getPrimal(cols(id(c))); }
-///\e
-Value primal(Col c) const { return _getPrimal(_lpId(c)); }
+/// Return the primal value of the expression
-///\e
+/// Return the primal value of the expression, i.e. the dot
+/// product of the primal solution and the expression.
+/// \pre The problem is solved.
 Value primal(const Expr& e) const {
-double res = e.constComp();
+double res = *e;
-for (std::map<Col, double>::const_iterator it = e.begin();
+for (Expr::ConstCoeffIt c(e); c != INVALID; ++c) {
-it != e.end(); ++it) {
+res += *c * primal(c);
-res += _getPrimal(_lpId(it->first)) * it->second;
 }
 return res;
 }
+/// Returns a component of the primal ray
-///\e
-Value dual(Row r) const { return _getDual(_lpId(r)); }
+/// The primal ray is solution of the modified primal problem,
-///\e
+/// where we change each finite bound to 0, and we looking for a
+/// negative objective value in case of minimization, and positive
+/// objective value for maximization. If there is such solution,
+/// that proofs the unsolvability of the dual problem, and if a
+/// feasible primal solution exists, then the unboundness of
+/// primal problem.
+///
+/// \pre The problem is solved and the dual problem is infeasible.
+/// \note Some solvers does not provide primal ray calculation
+/// functions.
+Value primalRay(Col c) const { return _getPrimalRay(cols(id(c))); }
+/// Return the dual value of the row
+/// Return the dual value of the row.
+/// \pre The problem is solved.
+Value dual(Row r) const { return _getDual(rows(id(r))); }
+/// Return the dual value of the dual expression
+/// Return the dual value of the dual expression, i.e. the dot
+/// product of the dual solution and the dual expression.
+/// \pre The problem is solved.
 Value dual(const DualExpr& e) const {
 double res = 0.0;
-for (std::map<Row, double>::const_iterator it = e.begin();
+for (DualExpr::ConstCoeffIt r(e); r != INVALID; ++r) {
-it != e.end(); ++it) {
+res += *r * dual(r);
-res += _getPrimal(_lpId(it->first)) * it->second;
 }
 return res;
 }
-///\e
+/// Returns a component of the dual ray
-bool isBasicCol(Col c) const { return _isBasicCol(_lpId(c)); }
+/// The dual ray is solution of the modified primal problem, where
-///\e
+/// we change each finite bound to 0 (i.e. the objective function
+/// coefficients in the primal problem), and we looking for a
+/// ositive objective value. If there is such solution, that
+/// proofs the unsolvability of the primal problem, and if a
+/// feasible dual solution exists, then the unboundness of
+/// dual problem.
+///
+/// \pre The problem is solved and the primal problem is infeasible.
+/// \note Some solvers does not provide dual ray calculation
+/// functions.
+Value dualRay(Row r) const { return _getDualRay(rows(id(r))); }
+/// Return the basis status of the column
+/// \see VarStatus
+VarStatus colStatus(Col c) const { return _getColStatus(cols(id(c))); }
+/// Return the basis status of the row
+/// \see VarStatus
+VarStatus rowStatus(Row r) const { return _getRowStatus(rows(id(r))); }
+///The value of the objective function
 ///\return
 ///- \ref INF or -\ref INF means either infeasibility or unboundedness
 /// of the primal problem, depending on whether we minimize or maximize.
 ///- \ref NaN if no primal solution is found.
 ///- The (finite) objective value if an optimal solution is found.
-Value primalValue() const { return _getPrimalValue()+obj_const_comp;}
+Value primal() const { return _getPrimalValue()+obj_const_comp;}
 ///@}
+LpSolver* newSolver() {return _newSolver();}
+LpSolver* cloneSolver() {return _cloneSolver();}
+protected:
+virtual LpSolver* _newSolver() const = 0;
+virtual LpSolver* _cloneSolver() const = 0;
 };
 /// \ingroup lp_group
 ///
 /// \brief Common base class for MIP solvers
-/// \todo Much more docs
+///
-class MipSolverBase : virtual public LpSolverBase{
+/// This class is an abstract base class for MIP solvers. This class
+/// provides a full interface for set and modify an MIP problem,
+/// solve it and retrieve the solution. You can use one of the
+/// descendants as a concrete implementation, or the \c Lp
+/// default MIP solver. However, if you would like to handle MIP
+/// solvers as reference or pointer in a generic way, you can use
+/// this class directly.
+class MipSolver : virtual public LpBase {
 public:
-///Possible variable (coloumn) types (e.g. real, integer, binary etc.)
+/// The problem types for MIP problems
+enum ProblemType {
+///Feasible solution hasn't been found (but may exist).
+UNDEFINED = 0,
+///The problem has no feasible solution
+INFEASIBLE = 1,
+///Feasible solution found
+FEASIBLE = 2,
+///Optimal solution exists and found
+OPTIMAL = 3,
+///The cost function is unbounded
+///
+///The Mip or at least the relaxed problem is unbounded
+UNBOUNDED = 4
+};
+///\name Solve the MIP
+///@{
+/// Solve the MIP problem at hand
+///
+///\return The result of the optimization procedure. Possible
+///values and their meanings can be found in the documentation of
+///\ref SolveExitStatus.
+SolveExitStatus solve() { return _solve(); }
+///@}
+///\name Setting column type
+///@{
+///Possible variable (column) types (e.g. real, integer, binary etc.)
 enum ColTypes {
-///Continuous variable
+///Continuous variable (default)
 REAL = 0,
 ///Integer variable
+INTEGER = 1
-///Unfortunately, cplex 7.5 somewhere writes something like
-///#define INTEGER 'I'
-INT = 1
-///\todo No support for other types yet.
 };
-///Sets the type of the given coloumn to the given type
+///Sets the type of the given column to the given type
-///
-///Sets the type of the given coloumn to the given type.
+///Sets the type of the given column to the given type.
+///
 void colType(Col c, ColTypes col_type) {
-_colType(_lpId(c),col_type);
+_setColType(cols(id(c)),col_type);
 }
 ///Gives back the type of the column.
-///
 ///Gives back the type of the column.
+///
 ColTypes colType(Col c) const {
-return _colType(_lpId(c));
+return _getColType(cols(id(c)));
 }
+///@}
-///Sets the type of the given Col to integer or remove that property.
-///
+///\name Obtain the solution
-///Sets the type of the given Col to integer or remove that property.
-void integer(Col c, bool enable) {
+///@{
-if (enable)
-colType(c,INT);
+/// The type of the MIP problem
-else
+ProblemType type() const {
-colType(c,REAL);
+return _getType();
 }
-///Gives back whether the type of the column is integer or not.
+/// Return the value of the row in the solution
-///
-///Gives back the type of the column.
+///  Return the value of the row in the solution.
-///\return true if the column has integer type and false if not.
+/// \pre The problem is solved.
-bool integer(Col c) const {
+Value sol(Col c) const { return _getSol(cols(id(c))); }
-return (colType(c)==INT);
-}
+/// Return the value of the expression in the solution
-/// The status of the MIP problem
+/// Return the value of the expression in the solution, i.e. the
-SolutionStatus mipStatus() const {
+/// dot product of the solution and the expression.
-return _getMipStatus();
+/// \pre The problem is solved.
-}
+Value sol(const Expr& e) const {
+double res = *e;
+for (Expr::ConstCoeffIt c(e); c != INVALID; ++c) {
+res += *c * sol(c);
+}
+return res;
+}
+///The value of the objective function
+///\return
+///- \ref INF or -\ref INF means either infeasibility or unboundedness
+/// of the problem, depending on whether we minimize or maximize.
+///- \ref NaN if no primal solution is found.
+///- The (finite) objective value if an optimal solution is found.
+Value solValue() const { return _getSolValue()+obj_const_comp;}
+///@}
 protected:
-virtual ColTypes _colType(int col) const = 0;
+virtual SolveExitStatus _solve() = 0;
-virtual void _colType(int col, ColTypes col_type) = 0;
+virtual ColTypes _getColType(int col) const = 0;
-virtual SolutionStatus _getMipStatus() const = 0;
+virtual void _setColType(int col, ColTypes col_type) = 0;
+virtual ProblemType _getType() const = 0;
+virtual Value _getSol(int i) const = 0;
+virtual Value _getSolValue() const = 0;
+public:
+MipSolver* newSolver() {return _newSolver();}
+MipSolver* cloneSolver() {return _cloneSolver();}
+protected:
+virtual MipSolver* _newSolver() const = 0;
+virtual MipSolver* _cloneSolver() const = 0;
 };
-///\relates LpSolverBase::Expr
-///
-inline LpSolverBase::Expr operator+(const LpSolverBase::Expr &a,
-const LpSolverBase::Expr &b)
-{
-LpSolverBase::Expr tmp(a);
-tmp+=b;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Expr
-///
-inline LpSolverBase::Expr operator-(const LpSolverBase::Expr &a,
-const LpSolverBase::Expr &b)
-{
-LpSolverBase::Expr tmp(a);
-tmp-=b;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Expr
-///
-inline LpSolverBase::Expr operator*(const LpSolverBase::Expr &a,
-const LpSolverBase::Value &b)
-{
-LpSolverBase::Expr tmp(a);
-tmp*=b;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Expr
-///
-inline LpSolverBase::Expr operator*(const LpSolverBase::Value &a,
-const LpSolverBase::Expr &b)
-{
-LpSolverBase::Expr tmp(b);
-tmp*=a;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Expr
-///
-inline LpSolverBase::Expr operator/(const LpSolverBase::Expr &a,
-const LpSolverBase::Value &b)
-{
-LpSolverBase::Expr tmp(a);
-tmp/=b;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator<=(const LpSolverBase::Expr &e,
-const LpSolverBase::Expr &f)
-{
-return LpSolverBase::Constr(-LpSolverBase::INF,e-f,0);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator<=(const LpSolverBase::Value &e,
-const LpSolverBase::Expr &f)
-{
-return LpSolverBase::Constr(e,f);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator<=(const LpSolverBase::Expr &e,
-const LpSolverBase::Value &f)
-{
-return LpSolverBase::Constr(-LpSolverBase::INF,e,f);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator>=(const LpSolverBase::Expr &e,
-const LpSolverBase::Expr &f)
-{
-return LpSolverBase::Constr(-LpSolverBase::INF,f-e,0);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator>=(const LpSolverBase::Value &e,
-const LpSolverBase::Expr &f)
-{
-return LpSolverBase::Constr(f,e);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator>=(const LpSolverBase::Expr &e,
-const LpSolverBase::Value &f)
-{
-return LpSolverBase::Constr(f,e,LpSolverBase::INF);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator==(const LpSolverBase::Expr &e,
-const LpSolverBase::Value &f)
-{
-return LpSolverBase::Constr(f,e,f);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator==(const LpSolverBase::Expr &e,
-const LpSolverBase::Expr &f)
-{
-return LpSolverBase::Constr(0,e-f,0);
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator<=(const LpSolverBase::Value &n,
-const LpSolverBase::Constr&c)
-{
-LpSolverBase::Constr tmp(c);
-LEMON_ASSERT(LpSolverBase::isNaN(tmp.lowerBound()), "Wrong LP constraint");
-tmp.lowerBound()=n;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator<=(const LpSolverBase::Constr& c,
-const LpSolverBase::Value &n)
-{
-LpSolverBase::Constr tmp(c);
-LEMON_ASSERT(LpSolverBase::isNaN(tmp.upperBound()), "Wrong LP constraint");
-tmp.upperBound()=n;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator>=(const LpSolverBase::Value &n,
-const LpSolverBase::Constr&c)
-{
-LpSolverBase::Constr tmp(c);
-LEMON_ASSERT(LpSolverBase::isNaN(tmp.upperBound()), "Wrong LP constraint");
-tmp.upperBound()=n;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::Constr
-///
-inline LpSolverBase::Constr operator>=(const LpSolverBase::Constr& c,
-const LpSolverBase::Value &n)
-{
-LpSolverBase::Constr tmp(c);
-LEMON_ASSERT(LpSolverBase::isNaN(tmp.lowerBound()), "Wrong LP constraint");
-tmp.lowerBound()=n;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::DualExpr
-///
-inline LpSolverBase::DualExpr operator+(const LpSolverBase::DualExpr &a,
-const LpSolverBase::DualExpr &b)
-{
-LpSolverBase::DualExpr tmp(a);
-tmp+=b;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::DualExpr
-///
-inline LpSolverBase::DualExpr operator-(const LpSolverBase::DualExpr &a,
-const LpSolverBase::DualExpr &b)
-{
-LpSolverBase::DualExpr tmp(a);
-tmp-=b;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::DualExpr
-///
-inline LpSolverBase::DualExpr operator*(const LpSolverBase::DualExpr &a,
-const LpSolverBase::Value &b)
-{
-LpSolverBase::DualExpr tmp(a);
-tmp*=b;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::DualExpr
-///
-inline LpSolverBase::DualExpr operator*(const LpSolverBase::Value &a,
-const LpSolverBase::DualExpr &b)
-{
-LpSolverBase::DualExpr tmp(b);
-tmp*=a;
-return tmp;
-}
-///\e
-///\relates LpSolverBase::DualExpr
-///
-inline LpSolverBase::DualExpr operator/(const LpSolverBase::DualExpr &a,
-const LpSolverBase::Value &b)
-{
-LpSolverBase::DualExpr tmp(a);
-tmp/=b;
-return tmp;
-}
 } //namespace lemon
 #endif //LEMON_LP_BASE_H

changeset 459	ed54c0d13df0
parent 458	7afc121e0689
child 470	81627fa1b007