1. What is GAMS?

2. Download GAMS
You can download the current GAMS distribution by going to
Then
1. Fill out the form

3. Download GAMS
2. After that user id and the
password will automatically
be ed to you within a
few minutes.
3. Then, follow the instruction
! Netscape Communicator
Users
! Internet Explorer Users
! FTP Users

4. Download GAMS
Example for FTP Users: Connect to GAMS ftp server ftp.gams.com.
with any ftp client. If you are asked for a password enter: insep34

5. Download GAMS
Example for FTP Users:
Then download setup.exe or all splitted files in the subdirectory
split if you have a slow or unstable connection. Detailed

6. Using GAMS IDE to Run GAMS
Steps to using GAMS IDE
1. Install GAMS and IDE
2. Start the IDE
3. Create and open files
4. House keeping
5. Run GAMS
7. Navigate around outputs

7. GAMS IDE - Install from CD
1. Install GAMS and the IDE on your computer
The IDE is automatically installed when GAMS is
installed. To install do the following steps
a. load the GAMS CD into your machine
b. start the installation using the
Windows Explorer and go into the
systems subdirectory called win
then double click on setup.exe

8. GAMS IDE - Install from GAMS download
1. Install GAMS and the IDE on your computer
The IDE is automatically installed when GAMS is
installed. To install do the following steps
a. go to the directory where you save your setup.exe
b. start the installation by double
click on setup.exe

9. GAMS IDE – Installation Process

10. GAMS IDE – Installation Process
c. supply the location for a
license (on your floppy or in
your directory)

11. GAMS IDE – Installation Process

12. GAMS IDE - Create an icon
d. right click on gamside.exe in the GAMS system directory,
choose “create shortcut” and drag the shortcut to your desktop

13. GAMS IDE - Start IDE
2. Start the IDE using it’s icon
a. open your explorer and create a new
sub-directory where you want to save
all your works
b. double click the IDE icon on your desktop
c. create a directory for your work by opening the File
menu and select Project and New project

14. GAMS IDE - Start IDE
d. define project name by typing a name for the project in
the “File name” area. All files (programs and output files)
associated with this project will be saved here.

15. GAMS IDE - Start IDE
The IDE uses a “Project” file for two purposes.
: to determine where all saved files are placed and where GAMS
looks for files when executing
: to save file names and program options

16. GAMS IDE - Open files
3. Open existing files
a. from the model library
Note library is sortable by name, area, type, contributor, and description by clicking on the heading.

17. GAMS IDE - Open your files
b. from your directory

18. GAMS IDE - Create a file
4. Create new files
a. open existing files and with save as dialogue change it’s name

19. GAMS IDE - Create a file
b. open the FILE menu and use the NEW option.
You will then get a file called untitled with an empty
screen that you can create (type) your own program.
When finished, save your program using the file SAVE or SAVEAS dialogue

20. GAMS IDE - Improving the display
5. Do a little housekeeping
: The IDE windows are not set up initially as well as they could be.
: To fix this use options dialog under File to alter their characteristics

21. GAMS IDE - Improving the display
The Output tab is used to set the output page width and length, date
and time format. Set page length to or 0 and the page width
range between

22. GAMS IDE - Improving the display
The Editor tab is used to set font type and size, tabs, and page
margin. Change font size if desired.

23. GAMS IDE - Improving the display
The Color tab is used to control color on a program. Alter it if you wish.

24. GAMS IDE - Improving the display
The Execute tab is used to locate the GAMS executable file and set
up the log process window. Check Update Process Window.

25. GAMS IDE - Selecting solvers
Solver tab is used to select a solver to solve a problem.
X = current
selection
. = available
- = not available
NLP using MINOS
LP using CPLEX
MCP using PATH

26. GAMS IDE - Run GAMS
6. Run GAMSIDE: clicking the run button or pressing F9
As GAMS is running, the process
window giving a log of steps will appear.

27. GAMS IDE - Run GAMS
Note: to get this window, use
Then drag the process window to the far right

28. GAMS IDE - GAMS log
6. Run GAMSIDE (con’t)
check if your file is ok
(36) indicate line it is on
execute your file
set up the problem
=> size of the problem
(23) indicate line SOLVE is on
=> start solver and gives a
name for which solver is
Used
GAMS restarts
=> GAMS stops without errors

29. GAMS IDE - Navigation with IDE
6. Run GAMSIDE (con’t)
! double click on lines in the process window to access output
! positioning of your access is determined by the color of the line
• blue lines => open *.LST file and jump to line in *.LST file
• black lines => open *.LST file and jump to a location of previous
blue line
• red lines => jump to *.gms file (program) where error occurs

30. GAMS IDE - Navigation with IDE
Double clicking on red lines => cursor will jump to *.gms file
(program) where error occurs
Note: always concentrate on fixing the first error and ignore the others since the next errors may be a result of the previous error.
Double clicking on black lines => cursor will jump to *.lst file (output) where error occurs

31. GAMS IDE - Equation list
7. Navigate around output
: look for first ---- to find equation listing in *.LST file
: look for the word ‘solution’ or ---- to find solution

32. GAMS Documentation
" GAMS documentations are accessible through the HELP menu

33. GAMS Documentation

34. GAMS Documentation
" GAMS documentations are accessible through the HELP menu

35. GAMS Documentation
" GAMS documentations are accessible through the HELP menu

36. Hands On
(handson1.gms, handson2.gms )
Learning Objectives:
1. Acquire basic ability to use IDE
2. Learn how to find and fix errors
3. Learn how to find and interpret GAMS solutions
Suggest things to do
1. Create a project in your directory and called “handson”
2. Do your housekeeping by setting up your options as you like
3. Open and run handson2.gms and navigate through *.LST file
4. Please find and fix those errors
5. Open handson1.gms (your program)
6. Run handson1.gms, then navigate through *.LST file, and find
optimal solutions, shadow prices, and reduced costs along
with their interpretations.

37. References