AMPL Model Reader Object
Systems and Computer Engineering
Carleton
University
Ottawa,
Canada
AMPL is a popular language for
describing mathematical programs – see www.ampl.com
for further information. The AMPL developers
provide a set of C language routines for hooking a solver or modeling system to
AMPL, however, it still requires significant programming effort and knowledge
to make the interface work smoothly. We
have simplified this task by creating an object wrapper for the interface
routines. This allows programmers to
simply reference the associated AMPL Model Reader object in their code, thereby
exposing the properties of the model and providing a set of useful methods.
Exposed properties include the names
of variables, constraints and objectives, variable bounds, constraint types,
etc. Methods include the ability to
calculate the value of a constraint or objective at a given point, ability to
return gradients at a point, etc. The
properties and methods exposed by the object can be conveniently viewed via the
object browser in the programming development environment.
The object also simplifies other
programming tasks. For example, an
appropriate dialog box is provided when the user wishes to locate an AMPL
model.
Two items are provided here:
- The AMPL Model Reader object. Two versions are available: a COM
object, and a .NET object. The
appropriate version should be downloaded and installed on your system.
- The source code for a demonstration program that shows
how to use the object. Two
versions are available: VB6 and VB.NET.
Read the help file after download to see how to attach the AMPL
Model Reader object to the demonstration program so that it will run.
Version History
- COM
object version 1.0 released August 13, 2003.
- .NET
object version 1.0 release August 14, 2003.
Download and Installation
The full-featured software is available for free
download. Instructions:
- Permission
to use the object is not needed, but as a courtesy, please email the author to indicate
that you are will be using it, and to be notified when new releases are
available.
- If you
use the object as part of your own software project, please acknowledge
the source.
COM Object
- The
installation files are WinZipped.
First unzip the files into an installation directory.
- Run
setup.exe. Choose a different
directory as the installation target.
- The
final result of running the installation is a DLL by the name of
amplModelReader.dll.
- Once
installed on your computer, you will need to make a reference to the
object in your development environment in order to use it. For example, in Visual Basic, you need
to open the dialog box under Project|References and then check the box
next to “AMPLModelReader”
.NET Object
- Download
AMPL Model Reader .NET object
- The
installation files are WinZipped.
First unzip the files into and installation directory.
- Run
setup.exe. Choose a different directory
as the installation target.
- The
final result of running the installation is:
- A .NET
DLL by the name of AMPLReaderClassLib.DLL located in the "drive:\windows
directory\system32" directory
- A directory
entitled “AMPLReaderDemo” which contains the VB source code for a
demonstration program which illustrates how to use the AMPL Model Reader
object.
- To
run the demonstration program, open the project on your computer and then
add the reference to the AMPLReaderClassLib.DLL. In Visual Basic .NET this is done by opening the dialog box
under Project|References and following the instructions.
Authors
Last
update: August 14, 2003.