/**
* Compares the given Chromosome to this Chromosome. This chromosome is considered to be "less
* than" the given chromosome if it has a fewer number of genes or if any of its gene values
* (alleles) are less than their corresponding gene values in the other chromosome.
*
* @param other the Chromosome against which to compare this chromosome
* @return a negative number if this chromosome is "less than" the given chromosome, zero if they
* are equal to each other, and a positive number if this chromosome is "greater than" the
* given chromosome
* @author Neil Rotstan
* @author Klaus Meffert
* @since 1.0
*/
public int compareTo(Object other) {
// First, if the other Chromosome is null, then this chromosome is
// automatically the "greater" Chromosome.
// ---------------------------------------------------------------
if (other == null) {
return 1;
}
int size = size();
IChromosome otherChromosome = (IChromosome) other;
Gene[] otherGenes = otherChromosome.getGenes();
// If the other Chromosome doesn't have the same number of genes,
// then whichever has more is the "greater" Chromosome.
// --------------------------------------------------------------
if (otherChromosome.size() != size) {
return size() - otherChromosome.size();
}
// Next, compare the gene values (alleles) for differences. If
// one of the genes is not equal, then we return the result of its
// comparison.
// ---------------------------------------------------------------
for (int i = 0; i < size; i++) {
int comparison = getGene(i).compareTo(otherGenes[i]);
if (comparison != 0) {
return comparison;
}
}
// Compare current fitness value.
// ------------------------------
if (m_fitnessValue != otherChromosome.getFitnessValueDirectly()) {
FitnessEvaluator eval = getConfiguration().getFitnessEvaluator();
if (eval != null) {
if (eval.isFitter(m_fitnessValue, otherChromosome.getFitnessValueDirectly())) {
return 1;
} else {
return -1;
}
} else {
// undetermined order, but unequal!
// --------------------------------
return -1;
}
}
if (m_compareAppData) {
// Compare application data.
// -------------------------
if (getApplicationData() == null) {
if (otherChromosome.getApplicationData() != null) {
return -1;
}
} else if (otherChromosome.getApplicationData() == null) {
return 1;
} else {
if (getApplicationData() instanceof Comparable) {
try {
return ((Comparable) getApplicationData())
.compareTo(otherChromosome.getApplicationData());
} catch (ClassCastException cex) {
/** @todo improve */
return -1;
}
} else {
return getApplicationData()
.getClass()
.getName()
.compareTo(otherChromosome.getApplicationData().getClass().getName());
}
}
}
// Everything is equal. Return zero.
// ---------------------------------
return 0;
}
