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ILOG Concert Technology provides a set of lightweight C++, Java and .NET objects for representing optimization problems. It is included as part of ILOG CPLEX, ILOG CP Optimizer and ILOG CP.
Easy algorithm application
Optimization models are separated from the algorithms that are used to find solutions. This allows problems to be decomposed into subproblems so that different algorithms can be applied to separate parts of a large scale problem.
Using Concert Technology, it's easy to experiment with different algorithmic strategies for the same problem. Concert Technology sets the foundation for current and future versions of the ILOG Optimization Suite by providing a unifying object-oriented API for all ILOG optimization products.
ILOG CP/CP Optimizer benefits
Users of ILOG CP Optimizer, as well as our first generation constraint programming engine, ILOG CP, will see the following benefits:
Solution decomposition
Because models are separate from search algorithms, it's easy to try different algorithms applied to the same model, in order to find the best algorithm for a particular problem. Model and algorithm separation also allows:
- Changing a problem so that a domain of a variable expands
- Relaxing part of an infeasible problem in order to find a solution
Multiphase search
It is now easier to split a problem into smaller
parts, write separate algorithms for each part and store solutions for the
individual parts.
Cooperation
The Concert framework facilitates:
- Automatic model extraction -- A constraint programming (CP) or linear
programming (LP) model can be automatically extracted and passed to the
corresponding solver.
- Solver cooperation -- Other algorithms can cooperate with constraint programming
techniques. Hybrid solutions that apply linear programming and constraint
programming can be created by combining ILOG CP Optimizer or ILOG CP with ILOG CPLEX.
- Nonlinear problem solving -- Numerical domain reduction algorithms
can be applied to a nonlinear problem over real variables.
- Local search -- This is now a part of ILOG CP.
ILOG CPLEX benefits
ILOG CPLEX users will find the following benefits from using ILOG Concert Technology
to develop applications:
C++, Java and .NET support for CPLEX
A complete, supported C++, Java and .NET API for CPLEX, including problem modifications, and access to all CPLEX algorithms and features.
Model representations
Modeling objects for representing mathematical
programs without matrices:
- Variables
- Constraints
- Models
- Model by stating constraints as expressions
- Column generation by stating columns as expressions corresponding to
the dual problem
Branch-and-cut control
Ability to control CPLEX Mixed Integer
Optimizer using modeling objects:
- Branch variable selection and direction
- User heuristics
- User cuts
- Node selection
- CPLEX automatically converts instructions given on the original problem
model to instructions on the internal presolved problem, preserving optimal
performance
Piecewise linear programming
Concert Technology can represent piecewise
linear programs. These problems are automatically converted to a linear programming
or mixed integer programming representation, and can be solved with CPLEX.
Developers can also elect to use ILOG Solver and CPLEX together. Solver
contains special domain reduction algorithms customized for piecewise linear
programs.
The differences between using the traditional CPLEX Callable Library and ILOG
Concert Technology are based on using different
representations for mathematical programs.
For an introduction to ILOG Concert Technology, listen to this Web seminar.
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