ObjectiveInstance¶
-
class
ObjectiveInstance¶
The ObjectiveInstance object stores the information regarding a specific instance of an objective.
The instances can be accessed through the function Objective.get of the parent
entity.
value()¶
-
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.
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¶
-
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.
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¶
-
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.
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¶
-
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.
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¶
-
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.
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