com.rapidminer.operator.preprocessing.discretization.AbsoluteDiscretization.java Source code

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Here is the source code for com.rapidminer.operator.preprocessing.discretization.AbsoluteDiscretization.java

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/**
 * Copyright (C) 2001-2017 by RapidMiner and the contributors
 * 
 * Complete list of developers available at our web site:
 * 
 * http://rapidminer.com
 * 
 * This program is free software: you can redistribute it and/or modify it under the terms of the
 * GNU Affero General Public License as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License along with this program.
 * If not, see http://www.gnu.org/licenses/.
*/
package com.rapidminer.operator.preprocessing.discretization;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;

import org.apache.commons.lang.ArrayUtils;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.set.SortedExampleSet;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.OperatorVersion;
import com.rapidminer.operator.annotation.ResourceConsumptionEstimator;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.operator.ports.metadata.SetRelation;
import com.rapidminer.operator.preprocessing.PreprocessingModel;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeBoolean;
import com.rapidminer.parameter.ParameterTypeCategory;
import com.rapidminer.parameter.ParameterTypeInt;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.parameter.conditions.BooleanParameterCondition;
import com.rapidminer.parameter.conditions.EqualTypeCondition;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;

/**
 * This operator discretizes all numeric attributes in the dataset into nominal attributes. This
 * discretization is performed by binning examples into bins of same size. The specified number of
 * equally sized bins is created and the numerical values are simply sorted into those bins, so that
 * all bins contain the same number of examples. Skips all special attributes including the label.
 *
 * @author Sebastian Land
 */
public class AbsoluteDiscretization extends AbstractDiscretizationOperator {

    static {
        registerDiscretizationOperator(AbsoluteDiscretization.class);
    }

    /** Indicates the number of used bins. */
    public static final String PARAMETER_SIZE_OF_BINS = "size_of_bins";

    /** Indicates if long range names should be used. */
    public static final String PARAMETER_RANGE_NAME_TYPE = "range_name_type";

    public static final String PARAMETER_SORTING_DIRECTION = "sorting_direction";

    public static final String PARAMETER_AUTOMATIC_NUMBER_OF_DIGITS = "automatic_number_of_digits";

    public static final String PARAMETER_NUMBER_OF_DIGITS = "number_of_digits";

    /**
     * Incompatible version, old version writes into the exampleset, if original output port is not
     * connected.
     */
    private static final OperatorVersion VERSION_MAY_WRITE_INTO_DATA = new OperatorVersion(7, 1, 1);

    public AbsoluteDiscretization(OperatorDescription description) {
        super(description);
    }

    @Override
    protected Collection<AttributeMetaData> modifyAttributeMetaData(ExampleSetMetaData emd, AttributeMetaData amd)
            throws UndefinedParameterError {
        AttributeMetaData newAMD = new AttributeMetaData(amd.getName(), Ontology.NOMINAL, amd.getRole());
        Set<String> valueSet = new TreeSet<String>();
        newAMD.setValueSet(valueSet, SetRelation.SUPERSET);
        if (getParameterAsInt(PARAMETER_RANGE_NAME_TYPE) == DiscretizationModel.RANGE_NAME_SHORT) {
            for (int i = 0; i < (int) Math.ceil(((double) emd.getNumberOfExamples().getNumber())
                    / getParameterAsInt(PARAMETER_SIZE_OF_BINS)); i++) {
                valueSet.add("range" + (i + 1));
            }
            switch (emd.getNumberOfExamples().getRelation()) {
            case AT_LEAST:
                newAMD.setValueSet(valueSet, SetRelation.SUPERSET);
                break;
            case AT_MOST:
                newAMD.setValueSet(valueSet, SetRelation.SUBSET);
                break;
            case EQUAL:
                newAMD.setValueSet(valueSet, SetRelation.EQUAL);
                break;
            case UNKNOWN:
                newAMD.setValueSet(valueSet, SetRelation.UNKNOWN);
                break;
            }
        }
        return Collections.singletonList(newAMD);
    }

    @Override
    public PreprocessingModel createPreprocessingModel(ExampleSet exampleSet) throws OperatorException {
        DiscretizationModel model = new DiscretizationModel(exampleSet);

        exampleSet.recalculateAllAttributeStatistics();
        // calculating number of bins
        int sizeOfBins = getParameterAsInt(PARAMETER_SIZE_OF_BINS);
        int numberOfBins = exampleSet.size() / sizeOfBins;
        int numberOfExamples = exampleSet.size();
        // add one bin if a remainder exists
        if (numberOfBins * sizeOfBins < numberOfExamples) {
            numberOfBins++;
        }
        HashMap<Attribute, double[]> ranges = new HashMap<Attribute, double[]>();

        int sortingDirection = getParameterAsInt(PARAMETER_SORTING_DIRECTION);

        for (Attribute attribute : exampleSet.getAttributes()) {
            if (attribute.isNumerical()) { // skip nominal and date attributes
                ExampleSet sortedSet = new SortedExampleSet(exampleSet, attribute, sortingDirection);
                double[] binRange = new double[numberOfBins];
                for (int i = 0; i < numberOfBins - 1; i++) {
                    int offset = (i + 1) * sizeOfBins - 1;
                    double infimum = sortedSet.getExample(offset).getValue(attribute);
                    offset++;
                    double supremum = sortedSet.getExample(offset).getValue(attribute);
                    // if targets equal values: Search for next different value
                    while (infimum == supremum && offset < numberOfExamples) {
                        supremum = sortedSet.getExample(offset).getValue(attribute);
                        offset++;
                    }
                    if (sortingDirection == SortedExampleSet.DECREASING) {
                        binRange[numberOfBins - 2 - i] = (infimum + supremum) / 2d;
                    } else {
                        binRange[i] = (infimum + supremum) / 2d;
                    }
                }
                binRange[numberOfBins - 1] = Double.POSITIVE_INFINITY;
                ranges.put(attribute, binRange);
            }
        }

        // determine number of digits
        int numberOfDigits = -1;
        if (getParameterAsBoolean(PARAMETER_AUTOMATIC_NUMBER_OF_DIGITS) == false) {
            numberOfDigits = getParameterAsInt(PARAMETER_NUMBER_OF_DIGITS);
        }

        model.setRanges(ranges, "range", getParameterAsInt(PARAMETER_RANGE_NAME_TYPE), numberOfDigits);
        return (model);
    }

    @Override
    public Class<? extends PreprocessingModel> getPreprocessingModelClass() {
        return DiscretizationModel.class;
    }

    @Override
    public List<ParameterType> getParameterTypes() {
        List<ParameterType> types = super.getParameterTypes();

        ParameterType type = new ParameterTypeInt(PARAMETER_SIZE_OF_BINS,
                "Defines the number of examples which should be used for each bin.", 1, Integer.MAX_VALUE, false);
        type.setExpert(false);
        types.add(type);

        types.add(new ParameterTypeCategory(PARAMETER_SORTING_DIRECTION,
                "Indicates if the values should be sorted in increasing or decreasing order.",
                SortedExampleSet.SORTING_DIRECTIONS, SortedExampleSet.DECREASING));

        types.add(new ParameterTypeCategory(PARAMETER_RANGE_NAME_TYPE,
                "Indicates if long range names including the limits should be used.",
                DiscretizationModel.RANGE_NAME_TYPES, DiscretizationModel.RANGE_NAME_LONG));

        type = new ParameterTypeBoolean(PARAMETER_AUTOMATIC_NUMBER_OF_DIGITS,
                "Indicates if the number of digits should be automatically determined for the range names.", true);
        type.registerDependencyCondition(new EqualTypeCondition(this, PARAMETER_RANGE_NAME_TYPE,
                DiscretizationModel.RANGE_NAME_TYPES, false, DiscretizationModel.RANGE_NAME_INTERVAL));
        types.add(type);

        type = new ParameterTypeInt(PARAMETER_NUMBER_OF_DIGITS,
                "The minimum number of digits used for the interval names (-1: determine minimal number automatically).",
                -1, Integer.MAX_VALUE, -1);
        type.registerDependencyCondition(
                new BooleanParameterCondition(this, PARAMETER_AUTOMATIC_NUMBER_OF_DIGITS, false, false));
        types.add(type);

        return types;
    }

    @Override
    public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
        return OperatorResourceConsumptionHandler.getResourceConsumptionEstimator(getInputPort(),
                AbsoluteDiscretization.class, attributeSelector);
    }

    @Override
    public boolean writesIntoExistingData() {
        if (getCompatibilityLevel().isAbove(VERSION_MAY_WRITE_INTO_DATA)) {
            return false;
        } else {
            // old version: true only if original output port is connected
            return isOriginalOutputConnected() && super.writesIntoExistingData();
        }
    }

    @Override
    public OperatorVersion[] getIncompatibleVersionChanges() {
        return (OperatorVersion[]) ArrayUtils.addAll(super.getIncompatibleVersionChanges(),
                new OperatorVersion[] { VERSION_MAY_WRITE_INTO_DATA });
    }
}