/*
* A redesigned Fitness Function calculator
* It takes into account the accuracy of the decision tree while classifying both, training and test examples
* The fitness score is a function of the weighted average of the two accuracies.
*/
private void calculateFitnessScore(double trainingWeight, double testingWeight)
throws OptimalScoreException {
DecisionTreeClassifier dtClassifier = getDecisionTree();
dtClassifier.TestAndFindAccuracy();
// Part 1 - Get training set accuracy
double trainingSetAccuracy = dtClassifier.getAccuracy();
// Part 2 - Get test set accuracy
SampleCollection test_samples =
new SampleCollection(
DataHolder.getTestingSamplesFileName(), DataHolder.getAttributesFileName());
// test_samples.discretizeSamples(Constants.DiscretizerAlgorithms.EQUAL_BINNING);
test_samples.discretizeSamplesBasedOnOtherSampleCollection(dtClassifier.getTrainingSamples());
dtClassifier.setTestingSamples(test_samples);
dtClassifier.TestAndFindAccuracy();
double testSetAccuracy = dtClassifier.getAccuracy();
fitnessScore =
(trainingWeight * trainingSetAccuracy + testingWeight * testSetAccuracy)
/ (trainingWeight + testingWeight);
// fitnessScore = trainingSetAccuracy; It was running very slowly that's why all this circus.
// We'll find a solution.
// fitnessScore = trainingSetAccuracy > testSetAccuracy ? trainingSetAccuracy : testSetAccuracy;
}
/*
* Used to reinitialize the static variables of this class, when DataHolder is updated, since static variables
* aren't updated automatically.
*/
public static void reInitializeStaticVariables() {
samples =
new SampleCollection(
DataHolder.getTrainingSamplesFileName(), DataHolder.getAttributesFileName());
FeatureSuperSet = samples.getfeatureList();
samples.discretizeSamples(Constants.DiscretizerAlgorithms.EQUAL_BINNING);
}
/*
* Initializes a decision tree that uses only the features present in the chromosome.
* It also calculates the fitness score of this chromosome.
*/
private void initDTfromChromosome(String chromosome) throws OptimalScoreException {
this.chromosome = chromosome;
calculateFitnessScore(TRAINING_SET_WEIGHT, TEST_SET_WEIGHT);
if (fitnessScore >= DataHolder.getFitnessScoreThreshold())
throw new OptimalScoreException(this);
}
