# Documentation of seltour

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## Function Synopsis

`NewChromIx = seltour(FitnV, Nsel, Dummy);`

## Help text

``` SELection by TOURnament

This function performs SELection by TOURnament.

Syntax:  NewChrIx = seltour(FitnV, Nsel)

Input parameters:
FitnV     - Column vector containing the fitness values of the
individuals in the population.
Nsel      - Number of individuals to be selected

Output parameters:
NewChromIx- Column vector containing the indexes of the selected
individuals relative to the original population, shuffeld.
The new population, ready for mating, can be obtained
by calculating OldChrom(NewChromIx,:).

The tournament size Tour is determined from the highest
fitness value ceil(max(FitnV)). If ranking was used, this
means ceil(SP);
FitnV = [1.0; 1.1; 1.9;  0.5; 1.3]; ==> Tour = 2;
FitnV = [1.6; 2.1; 3.05; 1.0; 0.4]; ==> Tour = 4;
The tournament size should be in [1, Nind]. If not, Tour is set
to one of these values and a message is displayed.
For Tour==1 tournament selection is identical to random selection
(no selective pressure).

Example:
% define fitness vector
FitnV = [.1; .9; 1.6; 2.0; 0.4; 1.3; 1.7; 0.7; 0.2];
% selects 6 indices from FitnV, Tour = 2;
NewChromIx = seltour(FitnV, 6);
% possible result
NewChromIx = [4; 7; 6; 7; 6; 5];
% Get selected individuals from population Chrom
SelChrom = Chrom(NewChromIx, :)
```

## Cross-Reference Information

This function calls 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.