public void MutateThrowsErrorIfNoValidGenomesExist()
{
// Create genome builder that does not accept any genome.
var genomeBuilder = GenomeBuilderTest.CreateCustomGenomeBuilder(
mutationRate: 0,
isValidFunction: candidate => false);
// Build a genome.
var genome = GenomeBuilderTest.BuildFittingGenome();
// Mutate will try to repair the genome and should throw an exception as that will never work.
Assert.Throws <TimeoutException>(() => genomeBuilder.Mutate(genome));
}
public void MakeGenomeValidThrowsIfNoValidGenomeExists()
{
// Create genome builder that does not accept any genome.
var genomeBuilder = GenomeBuilderTest.CreateCustomGenomeBuilder(
mutationRate: 0,
isValidFunction: candidate => false);
// Try to repair a genome.
var genome = GenomeBuilderTest.BuildFittingGenome();
Assert.Throws <TimeoutException>(() => genomeBuilder.MakeGenomeValid(genome));
}
public void MakeGenomeValidDoesNothingForValidGenome()
{
var genomeBuilder = GenomeBuilderTest.CreateGenomeBuilder();
var genome = GenomeBuilderTest.BuildFittingGenome();
var originalGenome = new Genome(genome);
genomeBuilder.MakeGenomeValid(genome);
Assert.True(
new Genome.GeneValueComparator().Equals(originalGenome, genome),
$"Genome should not have changed from {originalGenome} to {genome}.");
}
public void CrossoverWithEqualValuedGenomesGeneratesSameGenome()
{
var genomeBuilder = GenomeBuilderTest.CreateGenomeBuilder();
// Create parents with equal gene values.
var parent1 = GenomeBuilderTest.BuildFittingGenome();
var parent2 = GenomeBuilderTest.BuildFittingGenome();
// Do a crossover and check child's gene values.
var child = genomeBuilder.Crossover(parent1, parent2);
Assert.True(
GenomeBuilderTest.genomeValueComparer.Equals(child, parent1),
$"Crossover of equal valued genomes {parent1} and {parent2} produced child {child} with different values.");
}
public void MutateMayChangeEveryParameter()
{
// Create genome builder with a mutation rate of 1.
var configuration = new AlgorithmTunerConfiguration.AlgorithmTunerConfigurationBuilder()
.SetMutationRate(1)
.Build(maximumNumberParallelEvaluations: 1);
var genomeBuilder = new GenomeBuilder(GenomeBuilderTest.BuildParameterTree(), configuration);
// Create genome.
var genome = GenomeBuilderTest.BuildFittingGenome();
// Prepare structure to store which values have been mutated.
string[] identifiers =
{
GenomeBuilderTest.DecisionParameter,
GenomeBuilderTest.SmallValueParameter,
GenomeBuilderTest.DiscreteParameter,
GenomeBuilderTest.ContinuousParameter,
};
Dictionary <string, bool> hasBeenMutated = identifiers.ToDictionary(
identifier => identifier,
identifier => false);
Dictionary <string, IAllele> originalValues = identifiers.ToDictionary(
identifier => identifier,
identifier => genome.GetGeneValue(identifier));
// Do a lot of mutations.
for (int i = 0; i < GenomeBuilderTest.loopCountForRandomTests; i++)
{
genomeBuilder.Mutate(genome);
// After each one, check which genes have changed...
foreach (string identifier in identifiers)
{
bool valueChanged = !object.Equals(originalValues[identifier], genome.GetGeneValue(identifier));
if (valueChanged)
{
// ...and store them.
hasBeenMutated[identifier] = true;
}
}
}
// Finally check that everything has been changed at least once.
Assert.True(
hasBeenMutated.All(keyValuePair => keyValuePair.Value),
$"Genes {TestUtils.PrintList(hasBeenMutated.Where(keyValuePair => !keyValuePair.Value).Select(keyValuePair => keyValuePair.Key))} have not been mutated.");
}
public void ValidateGenomeReturnsFalseForWrongType()
{
// Create a genome builder.
var genomeBuilder = GenomeBuilderTest.CreateGenomeBuilder();
// Create correct genome.
var genome = GenomeBuilderTest.BuildFittingGenome();
Assert.True(genomeBuilder.IsGenomeValid(genome));
// Change a gene s.t. it has the wrong type.
genome.SetGene(GenomeBuilderTest.DiscreteParameter, new Allele <double>(3));
// Check method returns false now.
Assert.False(
genomeBuilder.IsGenomeValid(genome),
$"Genome {genome} was evaluated as valid even if gene 'int' was created as double.");
}
public void ValidateGenomeReturnsFalseForWrongDomain()
{
// Create a genome builder.
var genomeBuilder = GenomeBuilderTest.CreateGenomeBuilder();
// Create correct genome.
var genome = GenomeBuilderTest.BuildFittingGenome();
Assert.True(genomeBuilder.IsGenomeValid(genome));
// Change a gene s.t. it is outside of domain.
genome.SetGene(GenomeBuilderTest.ContinuousParameter, new Allele <double>(0.9));
// Check method returns false now.
Assert.False(
genomeBuilder.IsGenomeValid(genome),
$"Genome {genome} was evaluated as valid even if gene '{GenomeBuilderTest.ContinuousParameter}' was set to 0.9.");
}
public void MakeGenomeValidRepairsInvalidGenome()
{
// Invalid genomes must exist. We forbid having a value of 3 for a certain gene.
int forbiddenValue = 3;
Func <Genome, bool> doesNotHave3ForInt1To5 = candidate =>
!object.Equals(candidate.GetGeneValue(GenomeBuilderTest.SmallValueParameter).GetValue(), forbiddenValue);
// Create a genome builder implementing that check.
var genomeBuilder = GenomeBuilderTest.CreateCustomGenomeBuilder(
mutationRate: 0,
isValidFunction: doesNotHave3ForInt1To5);
var genome = GenomeBuilderTest.BuildFittingGenome();
genome.SetGene(GenomeBuilderTest.SmallValueParameter, new Allele <int>(forbiddenValue));
genomeBuilder.MakeGenomeValid(genome);
Assert.True(genomeBuilder.IsGenomeValid(genome), $"{genome} should be valid after repairing it.");
}
public void MutateChangesGivenGenomeIfMutationRateIs1()
{
// Create genome builder with a mutation rate of 1.
var configuration =
new AlgorithmTunerConfiguration.AlgorithmTunerConfigurationBuilder()
.SetMutationRate(1)
.Build(maximumNumberParallelEvaluations: 1);
var genomeBuilder = new GenomeBuilder(GenomeBuilderTest.BuildParameterTree(), configuration);
// Build a fitting genome and store original description.
var genome = GenomeBuilderTest.BuildFittingGenome();
string originalDescription = genome.ToString();
// Call mutate and check genome changed.
genomeBuilder.Mutate(genome);
Assert.NotEqual(
originalDescription,
genome.ToString());
}
public void MutateIsNoOperationIfMutationRateIs0()
{
// Create genome builder with a mutation rate of 0.
var genomeBuilder = GenomeBuilderTest.CreateGenomeBuilderWithoutRandomMutation();
// Build a fitting genome and store original description.
var genome = GenomeBuilderTest.BuildFittingGenome();
string originalDescription = genome.ToString();
// Check many times:
for (int i = 0; i < GenomeBuilderTest.loopCountForRandomTests; i++)
{
// If mutate is called, the genome does not change.
genomeBuilder.Mutate(genome);
Assert.Equal(
originalDescription,
genome.ToString());
}
}
public void MutateRespectsMutationRate()
{
// Create genome builder with a mutation rate of 0.35.
double mutationRate = 0.35;
var configuration =
new AlgorithmTunerConfiguration.AlgorithmTunerConfigurationBuilder()
.SetMutationRate(mutationRate)
.Build(maximumNumberParallelEvaluations: 1);
var genomeBuilder = new GenomeBuilder(GenomeBuilderTest.BuildParameterTree(), configuration);
// Create genome.
var genome = GenomeBuilderTest.BuildFittingGenome();
// For a lot of iterations:
IAllele oldGeneValue = genome.GetGeneValue(GenomeBuilderTest.ContinuousParameter);
int changeCount = 0;
int numberLoops = 1000;
for (int i = 0; i < numberLoops; i++)
{
// Mutate the genome ...
genomeBuilder.Mutate(genome);
// ... compare the continuous parameter gene...
IAllele newGeneValue = genome.GetGeneValue(GenomeBuilderTest.ContinuousParameter);
if (!object.Equals(newGeneValue, oldGeneValue))
{
changeCount++;
}
// ... and count the number of times it changes.
oldGeneValue = newGeneValue;
}
// Finally compare the number of mutations with the expected number.
double expectedNumberMutations = mutationRate * numberLoops;
Assert.True(
Math.Abs(expectedNumberMutations - changeCount) <= 0.1 * expectedNumberMutations,
"Number of mutations was not as expected.");
}
public void MutateRepairsInvalidGenomes()
{
// Invalid genomes must exist. We forbid having a value of 3 for a certain gene.
int forbiddenValue = 3;
Func <Genome, bool> doesNotHave3ForInt1To5 = candidate =>
!object.Equals(candidate.GetGeneValue(GenomeBuilderTest.SmallValueParameter).GetValue(), forbiddenValue);
// Create a genome builder implementing that check. It also should never mutate randomly
// so we can be sure the repair was not due to the mutation itself.
var genomeBuilder = GenomeBuilderTest.CreateCustomGenomeBuilder(
mutationRate: 0,
isValidFunction: doesNotHave3ForInt1To5);
// Build an invalid genome.
var genome = GenomeBuilderTest.BuildFittingGenome();
genome.SetGene(GenomeBuilderTest.SmallValueParameter, new Allele <int>(forbiddenValue));
// Mutate and check the broken gene was fixed.
genomeBuilder.Mutate(genome);
Assert.NotEqual(
forbiddenValue,
genome.GetGeneValue(GenomeBuilderTest.SmallValueParameter).GetValue());
}
