Getting Ready: Download GAMS and the UNI-CGE Model
1.
Download GAMS Modeling Software
To access, download and install the demo version of GAMS, follow these steps:
A. Go to the download page on the GAMS website at www.gams.com/download
B. Select
the Download that matches the operating system on your computer (Figure
1). Then click on the “Download” button.
This will download the Installation Wizard onto your computer. The installer
program will have an .exe suffix. You can install it into your Download folder,
or choose another folder.
Figure
1. Download Page on GAMS (29 April 2024)
C. Locate
and double-click on the installer program, and the installation will begin (Figure 2).
Figure 2. Double-click on the installer .exe file that you just downloaded
D. A series of screens will appear. Make these
selections:
i. Accept the GAMS Set-up Wizard
ii. Accept the default destination file for GAMS (unless you want to locate it
someplace else on your computer)
iii. Choose GAMS Studio version (Figure 3).
Figure 3. Choose the GAMS Studio version of GAMS
iv. Choose Demo license option (Figure 4). And, agree to write the license to the system directory, which is the default directory in which the GAMS software is being placed.
Figure
4. Choose the Demo license
2. Create a Directory and Download the UNI-CGE Model
Follow these steps to download the UNI-CGE
model:
A. Create a directory for your work in this course with a name like “Yourname_UNI.” You may want to create a folder in the directory with a name like “UNIModel” that will hold only the model and its associated files.
B. Download the UNI-CGEXX.zip from the course website, and save it in the directory (or subdirectory) you have just created. “XX” is the model version number. We occasionally update or improve the model.
C. Unzip the file. The UNI-CGE model is comprised of a suite of files. They are all contained in the .zip file All files in the .zip package must be placed in the same directory so that the GAMS program can locate them when you run the model.
D.
Types of files -
The main model is named UNI-CGEXX.gms. The gms
suffix denotes that it is a GAMS program file that can be run and solved. Some
files in the .zip file have an .inc suffix,
which stands for “include.” Inc.files are auxiliary files that are called into
the main model program to serve some function, such as report writing or
checking for errors. The .inc files are separated from the main program to
reduce clutter.
The files of
greatest interest to you are listed and described in Table 1. The other files
in the .zip file are necessary but have technical roles that we do not need to focus
on.
Table
1. Files contained in the UNI-CGE.ZIP
package
|
UNI-CGE FILES |
|
|
File Name |
What It Does |
|
UNI-CGE vXX.gms |
The most recent version of the CGE model |
|
1Calibaration-UNI.inc |
Uses data in the SAM to calibrate parameters and coefficients used in model equations |
|
1Repbase-UNI.inc |
Uses data in the SAM to prepare a report on the base data, including the macro SAM and tax rates |
|
1LES.inc |
Calculates the beta and gamma parameters in the LES function |
|
SAM-USA333.xlsx |
SAM for United States |
3. Open the UNI-CGE Model in GAMS - Method 1
Open your file directory app (in Windows, it is the File Explorer
app). Find the name of the model,
UNI-CGEXX.gms in the list of files (Figure 5). Double-click on the green arrow
on the left side of the model name. This will open the
model inside of the GAMS Studio app. The GAMS software should open
automatically.
Figure 5.
Finding the .GMS model file in the list of files
The name of your model will be on the left side of the GAMS
screen (Figure 6). This is GAMS’ Project
Explorer window. It lists all open files and projects.
Figure 6. File Explorer lists all open files and projects
If your model name is not shown, click on View>Project Explorer on the upper menu. Select Project Explorer (Figure 6). This will open a view with the list of all open files and projects.
Figure 7. Open Project Explorer window.
4. Open the UNI-CGE Model in GAMS - Method 2
Open
the GAMS Studio app. Click on “File” in the upper left corner (Figure 9), then select
“Open” from the drop--down menu.
Figure 9. Open the UNI-CGE Model file from within GAMS
Select UNI-CGEvXX.gms from the directory that you created for this course. This will open the UNI-CGE model. The model is ready to run!
Copyright: Cornerstone CGE CC 4.0 BY-NC-SA