use of org.kie.kogito.explainability.local.lime.HighScoreNumericFeatureZones in project kogito-apps by kiegroup.
the class DataUtils method boostrapFeatureDistributions.
/**
* Generate feature distributions from an existing (evantually small) {@link DataDistribution} for each {@link Feature}.
* Each feature intervals (min, max) and density information (mean, stdDev) are generated using bootstrap, then
* data points are sampled from a normal distribution (see {@link #generateData(double, double, int, Random)}).
*
* @param dataDistribution data distribution to take feature values from
* @param perturbationContext perturbation context
* @param featureDistributionSize desired size of generated feature distributions
* @param draws number of times sampling from feature values is performed
* @param sampleSize size of each sample draw
* @param numericFeatureZonesMap high feature score zones
* @return a map feature name -> generated feature distribution
*/
public static Map<String, FeatureDistribution> boostrapFeatureDistributions(DataDistribution dataDistribution, PerturbationContext perturbationContext, int featureDistributionSize, int draws, int sampleSize, Map<String, HighScoreNumericFeatureZones> numericFeatureZonesMap) {
Map<String, FeatureDistribution> featureDistributions = new HashMap<>();
for (FeatureDistribution featureDistribution : dataDistribution.asFeatureDistributions()) {
Feature feature = featureDistribution.getFeature();
if (Type.NUMBER.equals(feature.getType())) {
List<Value> values = featureDistribution.getAllSamples();
double[] means = new double[draws];
double[] stdDevs = new double[draws];
double[] mins = new double[draws];
double[] maxs = new double[draws];
for (int i = 0; i < draws; i++) {
List<Value> sampledValues = DataUtils.sampleWithReplacement(values, sampleSize, perturbationContext.getRandom());
double[] data = sampledValues.stream().mapToDouble(Value::asNumber).toArray();
double mean = DataUtils.getMean(data);
double stdDev = Math.pow(DataUtils.getStdDev(data, mean), 2);
double min = Arrays.stream(data).min().orElse(Double.MIN_VALUE);
double max = Arrays.stream(data).max().orElse(Double.MAX_VALUE);
means[i] = mean;
stdDevs[i] = stdDev;
mins[i] = min;
maxs[i] = max;
}
double finalMean = DataUtils.getMean(means);
double finalStdDev = Math.sqrt(DataUtils.getMean(stdDevs));
double finalMin = DataUtils.getMean(mins);
double finalMax = DataUtils.getMean(maxs);
double[] doubles = DataUtils.generateData(finalMean, finalStdDev, featureDistributionSize, perturbationContext.getRandom());
double[] boundedData = Arrays.stream(doubles).map(d -> Math.min(Math.max(d, finalMin), finalMax)).toArray();
HighScoreNumericFeatureZones highScoreNumericFeatureZones = numericFeatureZonesMap.get(feature.getName());
double[] finaldata;
if (highScoreNumericFeatureZones != null) {
double[] filteredData = DoubleStream.of(boundedData).filter(highScoreNumericFeatureZones::test).toArray();
// only use the filtered data if it's not discarding more than 50% of the points
if (filteredData.length > featureDistributionSize / 2) {
finaldata = filteredData;
} else {
finaldata = boundedData;
}
} else {
finaldata = boundedData;
}
NumericFeatureDistribution numericFeatureDistribution = new NumericFeatureDistribution(feature, finaldata);
featureDistributions.put(feature.getName(), numericFeatureDistribution);
}
}
return featureDistributions;
}
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