Var

class Var : public idol::Object<VarVersion, Var>

Variable modeling-old object.

The class is used to represent a variable in an optimization model.

Variables can be created by calling a constructor of Var, passing the optimization environment which will store the variable’s versions as argument. The variable can then be added to a model using the Model::add method.

Another approach is to directly use the Model::add_var method.

Var x = model.add_var(0, 1, Continuous, "x");

Public Functions

Var(Env &t_env, double t_lb, double t_ub, VarType t_type, std::string t_name = "")

Constructor.

Creates a new variable in the optimization environment.

If no name is given, a unique name in the environment is given.

Parameters:

t_env – The optimization environment.
t_lb – The lower bound (possibly -Inf) for the default version of the variable.
t_ub – The upper bound (possibly +Inf) for the default version of the variable.
t_type – The type for the default version of the variable.
t_name – The given name of the variable.

Var(Env &t_env, double t_lb, double t_ub, VarType t_type, Column &&t_column, std::string t_name = "")

Constructor.

Creates a new variable in the optimization environment.

If no name is given, a unique name in the environment is given.

Parameters:

t_env – The optimization environment.
t_lb – The lower bound (possibly -Inf) for the default version of the variable.
t_ub – The upper bound (possibly +Inf) for the default version of the variable.
t_type – The type for the default version of the variable.
t_column – The column for the default version of the variable.
t_name – The given name of the variable.

Var(Env &t_env, double t_lb, double t_ub, VarType t_type, const Column &t_column, std::string t_name = "")

Constructor.

Creates a new variable in the optimization environment.

If no name is given, a unique name in the environment is given.

Parameters:

t_env – The optimization environment.
t_lb – The lower bound (possibly -Inf) for the default version of the variable.
t_ub – The upper bound (possibly +Inf) for the default version of the variable.
t_type – The type for the default version of the variable.
t_column – The column for the default version of the variable.
t_name – The given name of the variable.

Var(const Var&) = default

Var(Var&&) = default

Var &operator=(const Var&) = default

Var &operator=(Var&&) = default

inline const std::string &name() const

Returns the name of the optimization object.

Returns:: The name of the optimization object.

inline unsigned int id() const

Returns the id of the optimization object.

Returns:: The id of the optimization object.

inline bool is_in(const Model &t_model) const

Returns true if the optimization object is part of the model t_model, false otherwise.

Parameters:: t_model – The model.
Returns:: True if the optimization object is part of the model t_model, false otherwise.

inline const ValueT &get(const Annotation<Var, ValueT> &t_annotation) const

Returns the value of the given annotation t_annotation associated to the object.

If no value is found, the default value of the annotation is returned. If no default value was set, an exception is thrown.

Template Parameters:: ValueT – The value type of the annotation.
Parameters:: t_annotation – The annotation.
Returns:: The value of the annotation.

inline void set(const Annotation<Var, ValueT> &t_annotation, ArgsT&&... t_args) const

Sets the value of the given annotation t_annotation associated to the object.

Template Parameters:

ValueT – The value type of the annotation.
ArgsT – The parameter pack types for constructing the value of the annotation.

Parameters:

t_annotation – The annotation.
t_args – The parameter pack arguments used to construct “in place” the value of the annotation.

Public Static Functions

template<unsigned int N = 1, unsigned int I = 0> static inline Vector<Var, N - I> make_vector(Env &t_env, const Dim<N> &t_dim, double t_lb, double t_ub, VarType t_type, const std::string &t_name = "")

Creates a (nested) vector of variables.

Example:

Env env;

auto x = Var::make_vector(env, Dim<2>(m, n), 0., 1., Continuous, "x");

std::cout << x[1][4].name() << std::endl; // "x_1_4"

Template Parameters:

N – The dimension of the (nested) vector.
I – Used for recursion.

Parameters:

t_env – The environment to store the variables.
t_dim – The number of elements in each dimension.
t_lb – The lower bound.
t_ub – The upper bound.
t_type – The type of the variables.
t_name – The given name of the variables.

Returns:

A (nested) vector of variables.

Friends

friend class impl::Env