Compare the difference in objective with different data

[林暐竣（Lin）]

Dear all,
  I want to compare the difference in objective with two data files in the same .mod and .run files. I have solve objective in same .mod file with two data files Individually. How can I count the difference in objective between them. Please let me know how to store the objective value in .run files in order to compare them. 

Thank you.

[AMPL Google Group]

Before the first solve, define a parameter where you will store the objective values. For example,

param ObjVal {1..2};

Suppose that your objective function is named TotalCost, Then after the first solve, save the objective value with this command:

let ObjVal[1] := TotalCost;

After the second solve, save the value with this command:

let ObjVal[2] := TotalCost;

At any later point in your .run file, the difference between the two objective values is given by this AMPL expression:

abs(ObjVal[1] - ObjVal[2])

Of course, you should substitute the actual name of your objective function for "TotalCost" in this example. Also, you can use ObjVal[1] and ObjVal[2] in other expressions besides the one shown in the example above.

--
Robert Fourer
am...@googlegroups.com

{#HS:2051444835-112552#}

[林暐竣]

Thank you for your help. I have handled this problem according to you.

AMPL Google Group <am...@googlegroups.com> 於 2022年10月29日 週六 凌晨12:56寫道：

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