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Optimisation in Feko
Feko offers state-of-the-art optimisation engines based on generic algorithm (GA) and other methods, which can be used to automatically optimise the design and determine the optimum solution.
Global Goal: Combining and Weighting of Multiple Goals
Specify the method for combining multiple goals. A weight or importance factor is assigned to the combined goal and optimised according to the combination type, for example, the average of the goals combined for the specified data.
Combining Goals
Use the goal combination tool to extract a single error value from a set of goals.

Welcome
Release Notes
See what's new in the latest release.
Get Started
The Feko Getting Started Guide contains step-by-step instructions on how to get started with Feko.
Examples
The Feko Example Guide contains a collection of examples that teaches you Feko concepts and essentials.
Introduction to Feko
Feko is a comprehensive electromagnetic solver with multiple solution methods that is used for electromagnetic field analyses involving 3D objects of arbitrary shapes.
CADFEKO
CADFEKO is used to create and mesh the geometry or model mesh, specify the solution settings and calculation requests in a graphical environment.
POSTFEKO
POSTFEKO, the Feko post processor, is used to display the model (configuration and mesh), results on graphs and 3D views.
EDITFEKO
EDITFEKO is used to construct advanced models (both the geometry and solution requirements) using a high-level scripting language which includes loops and conditional statements.
Feko Solution Methods
One of the key features in Feko is that it includes a broad set of unique and hybridised solution methods. Effective use of Feko features requires an understanding of the available methods.
Optimisation in Feko
Feko offers state-of-the-art optimisation engines based on generic algorithm (GA) and other methods, which can be used to automatically optimise the design and determine the optimum solution.
- Optimisation Workflow in CADFEKO
  The workflow for setting up an optimisation in CADFEKO is explained.
- Launching OPTFEKO (Windows)
  Use the most suitable option for launching OPTFEKO.
- Launching OPTFEKO (Linux)
  Use the most suitable option for launching OPTFEKO in Linux.
- Command Line Arguments for Launching OPTFEKO
  Use the command line arguments to pass additional information to OPTFEKO when it is launched.
- Optimisation Methods and Stopping Criteria
  The duration and accuracy of an optimisation depends on the selected optimisation method and stopping criteria.
- Optimisation Parameters
  Specify the variables to alter during the optimisation run.
- Optimisation Masks
  An optimisation mask is a graphical approach to define an optimisation search. More complex scenarios are handled by a mask, where the goal shape is visually known, for example, the desired bandpass and bandstop regions of a filter.
- Defining an Optimisation Goal
  An optimisation goal defines the request type to be optimised and the goal it will attempt to achieve.
- Global Goal: Combining and Weighting of Multiple Goals
  Specify the method for combining multiple goals. A weight or importance factor is assigned to the combined goal and optimised according to the combination type, for example, the average of the goals combined for the specified data.
  - Combining Goals
    Use the goal combination tool to extract a single error value from a set of goals.
  - Goal Weighting
    Specify a weighting for the combination of multiple goals.
- Optimisation Using .PRE File modifications
  Use optimisation with modifications made in the .pre file in EDITFEKO.
- Optimisation Solver Settings
  Make adjustments to the optimisation settings for a more computationally efficient solution.
Feko Utilities
The Feko utilities consist of PREFEKO, OPTFEKO, ADAPTFEKO, the Launcher utility, Updater and the crash reporter.
Description of the Output File of Feko
Feko writes all the results to an ASCII output file .out as well as a binary output file .bof for usage by POSTFEKO. Use the .out file to obtain additional information about the solution.
Feko Application Macros
A large collection of application macros are available for CADFEKO and POSTFEKO.
Scripts and Application Programming Interface (API)
CADFEKO and POSTFEKO have a powerful, fast, lightweight scripting language integrated into the application allowing you to create models, get hold of simulation results and model configuration information as well as manipulation of data and automate repetitive tasks.
Appendix
Reference information is provided in the appendix.

Combining Goals

Use the goal combination tool to extract a single error value from a set of goals.

On the Request tab, in the Optimisation group, click the

Combine Goals icon.

Figure 1. The Combine goal dialog.

The extraction type can be chosen as Maximum, Minimum or Average. When a set of goals are combined using this tool, only the minimum, maximum or average value of all of the errors of all of the goals in the set is taken.

In order to combine goals using the combination tool, goals in the same search in the same tree level should be selected. The Combine goals dialog (see Figure 1) is launched in which the Combination type is chosen. Goals are added to an existing combination by right-clicking on the combination in the tree, and selecting the type of goal to add. Goals are removed from the combination by deleting them. If all goals in a combination are deleted, then the combination is automatically removed. Goals can be copied out of a combination to the root of the goals tree by opening the right-click context menu for the particular goal and selecting Copy.

The Average, Minimum and Maximum options define how the evaluated errors of the goals in the combination should be reduced to one error value. For example, if Average is chosen, then the average error of the goals in the combination are returned, while Maximum returns the maximum error. Each combination is assigned a weighting that indicates how the error should be combined with other goals and combinations in the same level of the tree during the global fitness evaluation. The combination tools may be nested to as many levels as required.