Objective
=========

.. java:package:: com.ampl
   :noindex:

.. java:type:: public class Objective extends Entity<ObjectiveInstance>

   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 :java:ref:`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 :java:ref:`UnsupportedOperationException` if called for a non scalar objective.

   Otherwise, use the method :java:ref:`Objective.get` to obtain the objects of type :java:ref:`ObjectiveInstance`, from which to access all properties (see section :ref:`secAccessInstancesAndValues` for further information on how to access instances).

   To gain access to all the values in an entity (for all instances and all suffixes for that entities), see :java:ref:`Entity.getValues` and the :java:ref:`DataFrame` class.

Constructors
------------
Objective
^^^^^^^^^

.. java:constructor::  Objective()
   :outertype: Objective

Objective
^^^^^^^^^

.. java:constructor::  Objective(AMPL ampl, Engine engine, String name)
   :outertype: Objective

Methods
-------
astatus
^^^^^^^

.. java:method:: public String astatus()
   :outertype: Objective

   Return the AMPL status

   :throws UnsupportedOperationException: if the objective is not scalar

drop
^^^^

.. java:method:: public void drop()
   :outertype: Objective

   Drop all instances of this objective, corresponding to the AMPL code:

   .. parsed-literal::

      drop objectiveName;

exitcode
^^^^^^^^

.. java:method:: public int exitcode()
   :outertype: Objective

   Exit code returned by solver after most recent solve with this objective

   :throws UnsupportedOperationException: if the objective is not scalar
   :return: Exit code

get
^^^

.. java:method:: @Override public ObjectiveInstance get()
   :outertype: Objective

   Get the objective instance (valid for scalar objectives only).

   :throws UnsupportedOperationException: if the objective is not scalar.
   :throws IllegalStateException: if the entity has been deleted in the underlying AMPL interpreter

get
^^^

.. java:method:: @Override public ObjectiveInstance get(Object... key)
   :outertype: Objective

   Get the objective corresponding to the specified key. See :ref:`secAccessInstancesAndValues` for further information on how the key can be specified.

   :param key: Key of the instance to be found.
   :throws IllegalArgumentException: if trying to access an instance with the wrong number of keys (see :java:ref:`Entity.indexarity`)
   :throws IllegalStateException: if the entity has been deleted in the underlying AMPL interpreter
   :return: The objective instance corresponding to the specified key. Returns ``null`` if the specified key is not present.

get
^^^

.. java:method:: public ObjectiveInstance get(Tuple key)
   :outertype: Objective

   Get the objective instance corresponding to the specified key, expressed as a Tuple. See :ref:`secAccessInstancesAndValues` for further information on how the key can be specified.

   :param key: The indexing Tuple of the instance to be found
   :throws IllegalArgumentException: if trying to access an instance with the wrong indexarity (see :java:ref:`Entity.indexarity`)
   :throws IllegalStateException: if the entity has been deleted in the underlying AMPL interpreter
   :return: The objective instance corresponding to the specified key. Returns ``null`` if the specified key is not present.

message
^^^^^^^

.. java:method:: public String message()
   :outertype: Objective

   Result message returned by solver after most recent solve with this objective

   :throws UnsupportedOperationException: if the objective is not scalar

refreshInstances
^^^^^^^^^^^^^^^^

.. java:method:: @Override  void refreshInstances()
   :outertype: Objective

restore
^^^^^^^

.. java:method:: public void restore()
   :outertype: Objective

   Restore all instances of this objective, corresponding to the AMPL code:

   .. parsed-literal::

      restore objectiveName;

result
^^^^^^

.. java:method:: public String result()
   :outertype: Objective

   Result string returned by solver after most recent solve with this objective

   :throws UnsupportedOperationException: if the objective is not scalar

setDeclaration
^^^^^^^^^^^^^^

.. java:method:: @Override  void setDeclaration(String declaration)
   :outertype: Objective

sstatus
^^^^^^^

.. java:method:: public String sstatus()
   :outertype: Objective

   Return the solver status

   :throws UnsupportedOperationException: if the objective is not scalar

toString
^^^^^^^^

.. java:method:: @Override public String toString()
   :outertype: Objective

   String representation of the objective. Equivalent to the AMPL statement

   .. parsed-literal::

      show objectiveName;

value
^^^^^

.. java:method:: public double value()
   :outertype: Objective

   If the entity has only one objective (usually the case), get the corresponding value

   :throws UnsupportedOperationException: if the objective is not scalar
   :return: Value of the objective