Difference between revisions of "Optimization"
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===About the optimization tool=== | ===About the optimization tool=== | ||
| + | The in-built optimization tools is for formulating and solving LP and MIP problems. It is basically a graphical user interface to the [http://zimpl.zib.de/ ZIMPL optimization modelling language]. For solving a problem, external third-party solvers are used and directly linked to the optimization tool. Currently, the solvers available are | ||
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| + | *[http://lpsolve.sourceforge.net/ LPSolve], which is freely available, and | ||
| + | *[http://www.ilog.com/products/optimization/archive.cfm?acc=ggopt&gp=cplex&source=cpc&cmpn=cplex ILOG CPLEX], which is a very efficient, state-of-the-art solver. However, it is commercial and requires that the user has a licence. | ||
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| + | The linking to [http://scip.zib.de/scip.shtml SCIP/Soplex] is currently under development. | ||
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| + | The optimization model is linked to a Heureka-formatted SQL Server database used for storing input data, simulation data, and result data. This enables a seamless integration with the input data required by the optimization model, as well as direct presentation of optimization results in the form of tables, graphs, and maps. This simplifies the analysis and visualization of scenarios or plans of forest development and outputs. | ||
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| + | As an alternative to the integrated optimization tool, an [http://www.aimms.com AIMMS] model has been developed, which may be more suitable for a OR researcher or the very advanced user who needs maximum flexibility or maximum optimization performance. This model is also linked to the same database, but is run as a separate application. It also requires an AIMMS licence. | ||
===Instructions=== | ===Instructions=== | ||
Revision as of 13:00, 20 January 2010
About the optimization tool
The in-built optimization tools is for formulating and solving LP and MIP problems. It is basically a graphical user interface to the ZIMPL optimization modelling language. For solving a problem, external third-party solvers are used and directly linked to the optimization tool. Currently, the solvers available are
- LPSolve, which is freely available, and
- ILOG CPLEX, which is a very efficient, state-of-the-art solver. However, it is commercial and requires that the user has a licence.
The linking to SCIP/Soplex is currently under development.
The optimization model is linked to a Heureka-formatted SQL Server database used for storing input data, simulation data, and result data. This enables a seamless integration with the input data required by the optimization model, as well as direct presentation of optimization results in the form of tables, graphs, and maps. This simplifies the analysis and visualization of scenarios or plans of forest development and outputs.
As an alternative to the integrated optimization tool, an AIMMS model has been developed, which may be more suitable for a OR researcher or the very advanced user who needs maximum flexibility or maximum optimization performance. This model is also linked to the same database, but is run as a separate application. It also requires an AIMMS licence.
Instructions
Settings
Adding a variable
Adding a parameter which is linked to a state or revenue variable
- In the Optimization Model window, right-click in "Parameters" section and Select "Add new parameter"
- Type a name, for example "pulpWood" (without apostrophes)
- Let "Heureka result variable" be selected
- Click Next
- Select Financial Value > PulpWood Volume Total (if this is the variable you are interested in)
- Click Finish
To check what Heureka variable a certain parameter is linked to:
- Select the parameter
- In the Properties window for the parameter (under the syntax window), under Databinding > ResultProperty, you can see what Heureka variable the parameter is bounded to. If you click on it you can change the binding.