.. _secMATLABrefObjectiveInstance:

ObjectiveInstance
=================

.. mat:class:: ObjectiveInstance


The ObjectiveInstance object stores the information regarding a specific instance of an objective.
The instances can be accessed through the function :mat:meth:`Objective.get` of the parent
entity.  


value()
-------

.. mat:classmethod:: ObjectiveInstance.value()

**Syntax**
~~~~~~~~~~

``v = value()``
 
**Description**
~~~~~~~~~~~~~~~

``v = value()`` Get the current value of the objective instance 

**Output Arguments**
~~~~~~~~~~~~~~~~~~~~

``v``
   The current value of the objective instance
   
**Example**
~~~~~~~~~~~
     
Create an indexed objective z, get an instance and display its value. Then solve the problem and display the value again. 

.. code-block:: matlab

   ampl.eval('var x{i in 1..2} <= i;');
   ampl.eval('maximize z{i in 1..2}: x[i];');
   z = ampl.getObjective('z');
   instance = z.get(1);
   instance.value
   ampl.solve;
   instance.value
   
gives::

   ans =
     0

   ans =
     1


astatus
-------

.. mat:classmethod:: ObjectiveInstance.astatus()

**Syntax**
~~~~~~~~~~

``v = astatus``
 
**Description**
~~~~~~~~~~~~~~~

``astatus`` Return the AMPL status for this objective instance. 


**Output Arguments**
~~~~~~~~~~~~~~~~~~~~

``v``
   The AMPL status for this objective instance.

**Example**
~~~~~~~~~~~
     
Create an indexed objective z, get an instance and display its status. Then solve the problem and display it again. 

.. code-block:: matlab

   ampl.eval('var x{i in 1..2} <= i;');
   ampl.eval('maximize z{i in 1..2}: x[i];');
   z = ampl.getObjective('z');
   instance = z.get(1);
   instance.astatus
   ampl.solve;
   instance.astatus
   
gives::

   ans =
   in
  
   ans =
   in



exitcode
--------

.. mat:classmethod:: ObjectiveInstance.exitcode()

**Syntax**
~~~~~~~~~~

``v = exitcode``
 
**Description**
~~~~~~~~~~~~~~~

``exitcode`` Get exit code returned by solver after most recent solve with this objective. 


**Output Arguments**
~~~~~~~~~~~~~~~~~~~~

``v``
   The exit code returned by solver after most recent solve with this objective.

**Example**
~~~~~~~~~~~
     
Create an indexed objective z, get an instance and display its exitcode. Then solve the problem and display it again. 

.. code-block:: matlab

   ampl.eval('var x{i in 1..2} <= i;');
   ampl.eval('maximize z{i in 1..2}: x[i];');
   z = ampl.getObjective('z');
   instance = z.get(1);
   instance.exitcode
   ampl.solve;
   instance.exitcode
   
gives::

   ans =
   0
  
   ans =
   0
    

message
-------

.. mat:classmethod:: ObjectiveInstance.message()

**Syntax**
~~~~~~~~~~

``v = message``
 
**Description**
~~~~~~~~~~~~~~~

``message`` Get the result message returned by solver after most recent solve with this objective.  


**Output Arguments**
~~~~~~~~~~~~~~~~~~~~

``v``
   The result message returned by solver after most recent solve with this objective

**Example**
~~~~~~~~~~~
     
Create an indexed objective z, get an instance and display the solver message. Then solve the problem and display it again. 

.. code-block:: matlab

   ampl.eval('var x{i in 1..2} <= i;');
   ampl.eval('maximize z{i in 1..2}: x[i];');
   z = ampl.getObjective('z');
   instance = z.get(1);
   instance.message
   ampl.solve;
   instance.message
   
gives::

   ans =
   ?
  
   ans = 
   CBC 2.8.2 optimal, objective -1
   0 iterations 



result
------

.. mat:classmethod:: ObjectiveInstance.result()

**Syntax**
~~~~~~~~~~

``v = result``
 
**Description**
~~~~~~~~~~~~~~~

``result`` Get the result string returned by solver after most recent solve with this objective.  


**Output Arguments**
~~~~~~~~~~~~~~~~~~~~

``v``
   The result string returned by solver after most recent solve with this objective.

**Example**
~~~~~~~~~~~
     
Create an indexed objective z, get an instance and display its result string. Then solve the problem and display it again. 

.. code-block:: matlab

   ampl.eval('var x{i in 1..2} <= i;');
   ampl.eval('maximize z{i in 1..2}: x[i];');
   z = ampl.getObjective('z');
   instance = z.get(1);
   instance.result
   ampl.solve;
   instance.result
   
gives::

   ans =
   ?
 
   ans =
   solved