Represents an AMPL objective.
Note that, in case of a scalar objective, all the properties (corresponding to AMPL suffixes) of the objective instance can be accessed through methods like Objective::value(). The methods have the same name of the corresponding AMPL suffixes. See http://www.ampl.com/NEW/suffbuiltin.html for a list of the available suffixes.
All these methods throw an std::logic_error if called for a non scalar objective and an std::runtime_error if called on an entity which has been deleted in the underlying intepreter.
The instances, represented by the class ObjectiveInstance can be accessed via the operator Objective::operator[](), via the methods Objective::get() or via the iterators provided.
To gain access to all the values in an entity (for all instances and all suffixes for that entities), see Entity::getValues() and the DataFrame class.
Instance access
Methods to access the instances which are part of this Entity
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inline ObjectiveInstance get() const
Get the instance corresponding to a scalar entity.
- Throws
-
- Returns
The corresponding instance.
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inline ObjectiveInstance get(TupleRef index) const
Get the instance with the specified index.
- Parameters
index – The tuple specifying the index
- Throws
out_of_range – if an instance with the specified index does not exist
out_of_range – if the entity has been deleted in the underlying AMPL interpreter
ampl::UnsupportedOperationException – if the entity is scalar
- Returns
The corresponding instance
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inline ObjectiveInstance get(VariantRef v1) const
Get the instance with the specified index.
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inline ObjectiveInstance get(VariantRef v1, VariantRef v2) const
Get the instance with the specified index.
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inline ObjectiveInstance get(VariantRef v1, VariantRef v2, VariantRef v3) const
Get the instance with the specified index.
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inline ObjectiveInstance get(VariantRef v1, VariantRef v2, VariantRef v3, VariantRef v4) const
Get the instance with the specified index.
- Parameters
v1 – The VariantRef specifying the first element of the indexing tuple
v2 – The VariantRef specifying the second element of the indexing tuple
v3 – The VariantRef specifying the third element of the indexing tuple
v4 – The VariantRef specifying the fourth element of the indexing tuple
- Throws
out_of_range – if an instance with the specified index does not exist
runtime_error – if the entity has been deleted in the underlying AMPL interpreter
ampl::UnsupportedOperationException – if the entity is scalar
- Returns
The corresponding instance
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inline ObjectiveInstance operator[](TupleRef index) const
-
inline ObjectiveInstance operator[](VariantRef v1) const
Public Types
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typedef internal::CountedIterator<internal::EntityWrapper<ObjectiveInstance>> iterator
Iterator for entities, represented by an iterator pointing to elements of type std::pair<TupleRef, InstanceClass>
Public Functions
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inline double value() const
Get the value of the objective instance.
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inline std::string astatus() const
Return the AMPL status.
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inline std::string sstatus() const
Return the solver status.
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inline int exitcode() const
Exit code returned by solver after most recent solve with this objective.
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inline std::string message() const
Result message returned by solver after most recent solve with this objective.
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inline std::string result() const
Result string returned by solver after most recent solve with this objective.
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inline void drop()
Drop this objective.
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inline void restore()
Restore this objective (if it had been dropped, no effect otherwise)
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inline bool minimization() const
Get the sense of this objective.
- Returns
true if minimize, false if maximize
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inline iterator begin() const
Get an iterator pointing to the first instance in this entity.
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inline iterator end() const
Get an iterator pointing after the last instance in this entity.
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inline iterator find(TupleRef t) const
Searches the current entity for an instance with the specified index.
- Returns
an iterator to the wanted entity if found, otherwise an iterator to BasicEntity::end.
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inline StringArray getIndexingSets() const
Get the AMPL string representation of the sets on which this entity is indexed.
The obtained vector can be modified without any effect to the entity.
- Returns
The string representation of the indexing sets for this entity or an empty array if the entity is scalar
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inline DataFrame getValues() const
Get the principal values of this entity as a DataFrame. The specific returned
value depends on the
type of entity (see list below).
- For:
Variables and Objectives it returns the suffix val
Parameters it returns their values
Constraints it returns the suffix dual
Sets it returns all the of the set. Note that it does not
apply to indexed sets. See SetInstance::getValues
- Returns
A DataFrame containing the values for all instances
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inline DataFrame getValues(StringArgs suffixes) const
Get the specified suffixes value for all instances in a DataFrame.
- Parameters
suffixes – Suffixes to get
- Returns
A DataFrame containing the specified values
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inline std::size_t indexarity() const
Get the indexarity of this entity (sum of the dimensions of the indexing sets).
This value indicates the arity of the Tuple to be passed to the method BasicEntity::get() in order to access an instance of this entity. See the following AMPL examples
var x; # indexarity = 0
var y {1..2}; # indexarity = 1
var z {1..2,3..4}; # indexarity = 2
var zz {{(1, 2)}}; # indexarity = 2
- Returns
The sum of the dimensions of the indexing sets or 0 if the entity is not indexed
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inline bool isScalar() const
Check whether this entity is scalar.
Equivalent to testing whether indexarity() is equal to zero.
- Returns
True if the entity is scalar (not indexed over any set)
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inline std::string name() const
Get the name of this entity.
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inline std::size_t numInstances() const
Get the number of instances in this entity.
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inline void setValues(DataFrame data)
Set the values of this entiy to the correponding values of a
DataFrame indexed over the same sets (or a subset).
This function assigns the values in the first data column of
the passed dataframe to the entity the function is called from.
In particular, the statement:
x.setValues(y.getValues());
is semantically equivalent to the AMPL statement:
let {s in S} x[s] := y[s];
- Parameters
data – The data to set the entity to
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inline std::string toString() const
Returns a string representation of this entity (its declaration)
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inline StringArray xref() const
Get the names of all entities which depend on this one.
- Returns
An array with the names of all entities which depend on this one.