/**
* It is an error if the number of seed candidates is greater than the population size. In this
* case an exception should be thrown. Not throwing an exception is wrong because it would permit
* undetected bugs in programs that use the factory.
*/
@Test(expectedExceptions = IllegalArgumentException.class)
public void testTooManySeedCandidates() {
CandidateFactory<String> factory = new StringFactory(alphabet, candidateLength);
// The following call should cause an exception since the 3 seed candidates
// won't fit into a population of size 2.
factory.generateInitialPopulation(
2, Arrays.asList("abcdefgh", "ijklmnop", "qrstuvwx"), FrameworkTestUtils.getRNG());
}
/**
* Generate a completely random population. Checks to make sure that the correct number of
* candidate solutions is generated and that each is valid.
*/
@Test
public void testUnseededPopulation() {
CandidateFactory<String> factory = new StringFactory(alphabet, candidateLength);
List<String> population =
factory.generateInitialPopulation(populationSize, FrameworkTestUtils.getRNG());
assert population.size() == populationSize
: "Wrong size population generated: " + population.size();
validatePopulation(population);
}
@Test
public void testMaxDepth() {
final int maxDepth = 3;
CandidateFactory<Node> factory =
new TreeFactory(2, maxDepth, new Probability(0.6), Probability.EVENS);
List<Node> trees = factory.generateInitialPopulation(20, ExamplesTestUtils.getRNG());
for (Node tree : trees) {
// Make sure that each tree is no bigger than the maximum permitted.
assert tree.getDepth() <= maxDepth : "Generated tree is too deep: " + tree.getDepth();
}
}
/**
* Generate a random population with some seed candidates. Checks to make sure that the correct
* number of candidate solutions is generated and that each is valid.
*/
@Test
public void testSeededPopulation() {
CandidateFactory<String> factory = new StringFactory(alphabet, candidateLength);
String seed1 = "cdefghij";
String seed2 = "bbbbbbbb";
List<String> population =
factory.generateInitialPopulation(
populationSize, Arrays.asList(seed1, seed2), FrameworkTestUtils.getRNG());
// Check that the seed candidates appear in the generated population.
assert population.contains(seed1) : "Population does not contain seed candidate 1.";
assert population.contains(seed2) : "Population does not contain seed candidate 2.";
validatePopulation(population);
}