# Documentation of obj4wings

Global Index (all files) (short | long) | Local contents | Local Index (files in subdir) (short | long)

## Function Synopsis

`ObjVal = obj4wings(Chrom, P1, P2)`

## Help text

``` OBJective function FOUR-WINGS.

This function implements the continuous and discrete variant of the
Four-Wings function. The continuous version is a unimodal function
with niveaulines resembling conjugated hyperbolas. Because of the
low slope the surface of the discrete version consists of wide
plateaus. The area of the plateaus increase with their niveau.

This function is defined as stepfun4 function in:%
Jain, Clusterbasierte Abbruchkriterien fuer den Evolutionaeren Test.
Diploma-thesis, Technical University of Berlin, Department of
Computer Science, chapter 5.1, 1999.

Syntax: ObjVal = obj4wings(Chrom, P1, P2)

Input parameters:
Chrom     - Matrix containing the chromosomes of the current
population. Each row corresponds to one individual's
string representation.
If Chrom == [NaN xxx]  or
Chrom == [NaN xxx yyy],
then special values will be returned, see Output parameters
xxx == 1 (or []) return boundaries
xxx == 2 return title
yyy == 0 return title of continuous variant
yyy == 1 return title of discrete variant
xxx == 3 return value of global minimum
P1        - (Optional) Number indicating which variant is used,
if Chrom is not NaN or [].
P1 = 1  use discrete version
P1 = 0  use continuous version
If P1 is omitted or P1 = [] the continuos version
is used (P1 = 0).

Output parameters:
ObjVal    - Column vector containing the objective values of the
individuals in the current population.
if called with
Chrom == [NaN xxx] or Chrom == [NaN xxx yyy],
then ObjVal contains
xxx == 1 (or []), matrix with the boundaries of
the varaibles
xxx == 2, text with the title of the function
yyy omitted: title of continuous variant
yyy = 0      title of continuous variant
yyy = 1      title of discrete variant
xxx == 3, value of global minimum

Examples:

% continuous variant of the Four-Wings function
>> obj4wings(Chrom)

% discrete variant of the Four-Wings function
>> obj4wings(Chrom, 1)
```

## Cross-Reference Information

This function is called by
 GEATbx: Main page  Tutorial  Algorithms  M-functions  Parameter/Options  Example functions  www.geatbx.com

This document is part of version 3.8 of the GEATbx: Genetic and Evolutionary Algorithm Toolbox for use with Matlab - www.geatbx.com.
The Genetic and Evolutionary Algorithm Toolbox is not public domain.