Comparative Analysis Multiple Submissions vs. LoopsAGEC 641 Lab, Fall 2010Mario Andres Fernandez

Based on material written by Gillig and McCarl; Improved upon by many previous lab instructors.Special thanks to Yuquan “Wolfgang” Zhang

Comparative AnalysisAs is often (always) the case, one is interested to see outcomes

under different scenarios.

Two ways to conduct comparative analysis

Use multiple GAMS submissions or multiple solves generating

report writing output and then manually comparing the

analysis results

Use the GAMS LOOP procedure and set up a comparative

scenario analysis system that creates cross scenario

comparison tables

Example

ScenariosWhat if one has a RAP (risk aversion parameter) of “1.5” or “5.0”?

Multiple GAMS SubmissionsReport writing commands use values from the most recent solution.

Multiple GAMS Submissions

Multiple GAMS Submissions

Multiple GAMS Submissions: Percentage Change

Scenario Comparative Report

Loop

Loop

Loop: Structural Modification

Increasing run efficiency using the Save and Restart procedure. We can associate a set of execution time parameters with a file

Save work files: s = .\t\a1Restart work files: r = .\t\a1

(1)

(2)