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Basic LP tasks: problem statement and solving; solution analysis Description The first model (file chess.mos) is a small, introductory
problem to modeling with Mosel that shows the basic
features of the Mosel language:
- formulation of a simple LP/IP problem
- solving an optimization problem
- solution printout
- formulating and solving a simple LP problem
- defining a set of variables and an array of descriptions for the variables (to be used in the output printing)
- Solve the MIP problem.
- Fix all discrete variables to their solution values.
- Re-solve the remaining LP problem.
- Retrieve the solution information.
Further explanation of this example:
'Mosel User Guide',
Chapter 1 Getting started with Mosel and Section 8.1 Initializing sets, or the book 'Applications of optimization with Xpress-MP', Section 1.3 Solving the chess set problem.
Source Files
chess.mos (!******************************************************* * Mosel Example Problems * * ====================== * * * * file chess.mos * * `````````````` * * Example for the use of the Mosel language * * (Small LP-problem) * * * * (c) 2008 Fair Isaac Corporation * * author: Bob Daniel, 2001 * *******************************************************!) model Chess uses "mmxprs" ! we need the optimizer declarations small, large: mpvar ! the decision variables end-declarations ! Now we have the constraints mc_time:= 3*small + 2*large <= 400 ! limit on available machine time wood:= small + 3*large <= 200 ! limit on available wood maximize( 5*small + 20*large ) ! solve, defining the objective function writeln writeln("Here are the LP results") writeln("Objective value is ", getobjval) writeln("Make ", small.sol, " small sets, and ", large.sol, " large sets") small is_integer large is_integer maximize( 5*small + 20*large ) ! solve, defining the objective function writeln writeln("Here are the IP results") writeln("Objective value is ", getobjval) writeln("Make ", small.sol, " small sets, and ", large.sol, " large sets") end-model | |||||||||||||||||||

Copyright 2017 Fair Isaac Corporation. |