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1Getting Started Chapter 1
Getting Started
Overview
In this chapter you will:
• meet Xpress-Mosel and the Xpress-Optimizer;
• be introduced to the interfaces through which to use them;
• discover how this book is organized and what you should read.
Introduction
Xpress-MP is a mathematical modeling and optimization software
suite, providing tools for the formulation, solution and analysis of
linear, quadratic and integer programming problems. Based on the
powerful components, Xpress-Mosel and the Xpress-Optimizer, the
suite comprises a collection of interfaces, addressing the diversity of
users’ needs, both in problem solving and embedding Xpress-MP
technology within their own custom products.
This book provides an introduction to using the major components of
Xpress-MP and, as such, is ideal for getting new users up and running
immediately. ... Many of the reference manuals
that accompany the Xpress-MP software suite assume some
knowledge of the material contained in Xpress-MP Essentials and it is
recommended that all users familiarize themselves with this guide
before continuing.
We begin by briefly describing the components and interfaces of
Xpress-MP and explain how they inter-relate. ...
It should be noted that this book does not contain any details of the
installation and setting up of Xpress-MP products. ...
Xpress-MP Components and Interfaces
Xpress-Mosel
The two basic components of Xpress-MP are Xpress-Mosel and the
Xpress-Optimizer. ... To this end, the
Optimizer is included as a library module, allowing complicated
There is also a third,
Xpress-BCL, which is
available only to
library users. ...
The Xpress-Optimizer
At the core of the Xpress-MP suite, the Xpress-Optimizer represents
decades of research and development in solution methods for linear
programming (LP), quadratic programming (QP) and mixed integer
programming (MIP) problems. ...
For the very hardest MIP problems, Xpress-MP provides the parallel
MIP Optimizer, designed to work on both a heterogeneous network
of PCs and/or workstations, and on shared memory multiprocessor
computers, to exploit all the computing power at your disposal. ...
Xpress-IVE
Xpress-IVE, the Xpress Interactive Visual Environment, is a complete
modeling and optimization development environment running under
Microsoft Windows. ...
Combining ease of use with the powerful modeling and optimization
features that Xpress-MP users have come to enjoy, IVE is ideal for
developing and debugging prototype models.
Console Xpress
Console Xpress comprises the main stand-alone executables, mosel
and optimizer. ...
We have found that Console Xpress products satisfy the needs of many
commercial users. Having developed your model with Xpress-IVE, you
can rapidly build production systems by wrapping Console Xpress
components in batch files or shell scripts, and tune the optimization
algorithms to solve your largest data instances.
The Xpress-MP Libraries
For more specialized applications, we offer the Xpress-MP Libraries,
providing access to the Mosel and Optimizer components from within
your own C/C++, Java and Visual Basic applications. The main
advantages of the Xpress-MP Libraries are that your own applications
can interact tightly with the functionality provided by Xpress-MP and
that greater flexibility exists to develop customized applications to
suit your needs. Under Windows, the Xpress-MP Libraries are
available as DLLs, providing a standard programming interface for
integrating Xpress-MP components within your Windows
applications. For UNIX users, the Xpress-MP Libraries are available as
shared object libraries.
On one level the Xpress-MP Libraries may be used simply to build
stand-alone applications using the basic model building and
optimization functionality available in all Xpress-MP products. ...
For users wishing to build custom applications and develop specialized
heuristics, the Xpress-MP Libraries offer a much higher level of
functionality. ...
For first-time users or for developing new models, Xpress-IVE provides
the simplest interface to the Xpress-MP software. ...
To operate a production system using modeling and/or optimization,
Console Xpress can be used to build batch processing applications. ...
If you are developing software such as Windows applications for your
end-user, the Xpress-MP Libraries offer the best interface. ...
How to Read this Book
Structure of the Book
This book assumes as a prerequisite that the Xpress-MP software you
wish to use has already been installed and no details of installation are
given here. ...
The following three chapters (2 – 4) are of particular interest to new
users, discussing the different Xpress-MP interfaces: Xpress-IVE,
Console Xpress and the Xpress-MP Libraries. ... The first of these, Chapter 5, “Modeling with Xpress-MP”,
introduces many of the major features of the modeling language,
incrementally developing a simple model and exploring the benefits
of versatile modeling. ... The
treatment here is only cursory, however, and further details on these
topics may be found in the Xpress-Mosel Reference Manual. ...
Points in the margin
Summary
In this chapter we have learnt:
about the main components of the Xpress-MP software
suite, Mosel and the Optimizer;
about the three interfaces to the main components,
Xpress-IVE, Console Xpress and the Xpress-MP Libraries;
which interface is best suited to your needs.
2Xpress-IVE Chapter 2
Xpress-IVE
Overview
In this chapter you will:
• work with projects and model program files in the Xpress-IVE interface;
• input simple models and solve them;
• export and input problems as matrix files;
• learn how to customize the look of the Xpress-IVE environment.
Getting Started
Xpress-IVE is the graphical user interface to Xpress-Mosel and the
Xpress-Optimizer for users of Microsoft Windows, providing a simple
development environment in which to learn about and use Xpress-MP
optimization tools. ...
The IVE interface brings together the two main components of the
Xpress-MP suite, Mosel and the Optimizer, in a single graphical
environment for easier use. Implementing the powerful Mosel model
programming language, complicated models can be developed and
solved with the minimum of trouble, making IVE the ideal starting
point for new users of Xpress-MP software.
Starting Xpress-IVE
During installation, a folder of icons is added to the Start Menu. Using
this, IVE can be started by clicking on the Start button, choosing
Programs, Xpress-MP and finally Xpress-IVE. ...
All Xpress-MP products employ a security system as an integral part of
the software which must be set up during the installation process for
all features of the product to be enabled. If set up incorrectly, or if
used without a license, Xpress-MP will be started in ‘trial mode’ and a
warning will be displayed along the top of the window stating ‘Trial
Version — commercial use prohibited’. ... If this occurs
and you have a current license for Xpress-MP software, refer to the
‘readme’ files for details of setting up the security system correctly. ...
Obtaining Further Information from Xpress-IVE
Knowing the maximum amount of profit that we can make in our
model is certainly useful, but what values should the decision variables
take in order to produce this? ...
"Solution
graphs…"
5Modeling with Xpress-MP Chapter 5
Modeling with
Xpress-Mosel
Overview
In this chapter, you will:
• construct simple models using the Mosel model programming language;
• develop versatile models through the use of subscripted variables, and constants;
• learn about separation of model data from model structure;
• learn about the use of data files and parameters.
Introduction
Over the course of the last few chapters we have seen how each of the
interfaces for Xpress-MP can be used to load and solve a simple model,
obtaining the optimal solution to the linear problem. ...
The Xpress-Mosel model programing language can often be used in
many ways to model the same problem and the examples given here
will represent just one approach to this. ...
Entering the Model into Xpress-Mosel
Models specified using the Mosel model programming language are
divided up into a number of blocks, the outermost being the model
block. ...
This model is on the
Xpress-MP CD as file
burglar1. ... Item: 1, 2, 3, 4, 5, 6, 7, 8
WEIGHT := [ 2, 20, 20, 30, 40, 30, 60, 10]
VALUE := [ 15,100, 90, 60, 40, 15, 10, 1]
This model is on the
Xpress-MP CD as file
burglar2. ... Constraint: weight restriction
TotalWeight:= sum(i in Items) x(i)*WEIGHT(i)<=102
maximize(TotalValue)
writeln("Objective value is ", getobjval)
forall(i in Items) writeln(" x(",i,") = ",
getsol(x(i)))
writeln
end-model
This model is on the
Xpress-MP CD as file
burglar3. ... Constraint: weight restriction
TotalWeight:=sum(i in Items) x(i)*WEIGHT(i)<=MAXWT
maximize(TotalValue)
writeln("Objective value is ", getobjval)
forall(i in Items) writeln(" x(",i,") = ",
getsol(x(i)))
writeln
end-model
This model is on the
Xpress-MP CD as file
burglar4. ...
This model is on the
Xpress-MP CD as file
burglar5. ... 14 Solving the Hiker Problem
C:Mosel Files>mosel
** Xpress-Mosel **
(c) Copyright Dash Associates 1998-zzzz
>load burglar5
>run WeightFile=Data/hiker. ... Mosel sets may be defined for any of
the elementary types: the basic types (integer, real, string and
boolean) and the Xpress-MP types (mpvar and linctr). ... 2 Using set comparison operators
model "Set Comparisons"
declarations
RAINBOW = {"red","yellow","orange","green",
"blue","indigo","violet"}
BRIGHT = {"orange","yellow"}
DARK = {"blue","brown","black"}
end-declarations
writeln("BRIGHT is included in RAINBOW: ",
BRIGHT<=RAINBOW)
writeln("BRIGHT is not the same as DARK: ",
BRIGHT<>DARK)
writeln("RAINBOW contains DARK: ", RAINBOW>=DARK)
end-model
Working with Arrays
In contrast to sets, arrays are ordered collections of objects of the same
type and may be defined for any of the elementary types: the basic
types (integer, real, string and boolean) and the Xpress-MP
types (mpvar and linctr). ... To do so requires the use of the
library module mmodbc, in addition to an extra authorization in your
Xpress-MP license. ... When data is imported into
Xpress-MP from a spreadsheet, the first row in the marked range is
always assumed to contain column headings and is consequently
ignored. ... 23 shows the use of this program from Console
Xpress. ...
keyword (in Mosel)
A keyword in an Xpress-MP model is either a model command or else
introduces / terminates a block. ... Often used to mean the Xpress-MP
representation of the problem. ... By convention the value is written
on the right hand side of the constraint, although this is not necessary
in Xpress-MP. ... In
Xpress-MP the ordering is supplied in a ‘reference row’, which may be
an ordinary constraint or a separate unconstraining constraint. ...
Xpress-MP
Essentials
Approximate Word count = 16915
Approximate Pages = 67.7
(250 words per page double spaced)
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