Application: gvSIG desktop

package org.gvsig.raster.lib.buffer.impl.statistics;

import java.util.ArrayList;

import java.util.List;

import org.gvsig.raster.lib.buffer.api.Band;

import org.gvsig.raster.lib.buffer.api.BufferManager;

import org.gvsig.raster.lib.buffer.api.statistics.HistogramBand;

import org.gvsig.raster.lib.buffer.api.statistics.HistogramClass;

import org.gvsig.raster.lib.buffer.api.statistics.StatisticsBand;

/**

 * @author fdiaz

 *

 */

public class HistogramOperation implements StatisticalOperation {

    private StatisticsBand statisticsBand;

    private List<HistogramClass> histogramClasses;

    private HistogramBand histogramBand;

    private Band band;

    /**

     * @param statisticsBand

     * @param band

     */

    public HistogramOperation(StatisticsBand statisticsBand, Band band) {

        this.statisticsBand = statisticsBand;

        this.band = band;

    }

    @Override

    public void pre() {

        int dataType = this.statisticsBand.getDataType();

        if(dataType == BufferManager.TYPE_DOUBLE || dataType == BufferManager.TYPE_FLOAT){

            calculateHistogramClasses();

            histogramBand = new DefaultHistogramBand(band, this.histogramClasses);

        } else {

            histogramBand = new DefaultHistogramBand(band);

        }

    }

    private void calculateHistogramClasses() {

        int classesNumber = new Double(Math.ceil(Math.sqrt(this.statisticsBand.getBandLength()-this.statisticsBand.getNoDataValuesCount()))).intValue();

        histogramClasses = new ArrayList<HistogramClass>(classesNumber);

        double range = this.statisticsBand.getMaximum()-this.statisticsBand.getMinimum();

        double widthInterval = range/classesNumber;

        double minInterval = this.statisticsBand.getMinimum();

        double maxInterval; // = this.statisticsBand.getMaximum();

        for(int i=0; i<classesNumber-1; i++){

            maxInterval = minInterval+widthInterval;

            DefaultHistogramClass histogramClass = new DefaultHistogramClass(minInterval, maxInterval);

            histogramClass.setValue(0);

            histogramClasses.add(histogramClass);

            minInterval = maxInterval;

        }

        DefaultHistogramClass histogramClass = new DefaultHistogramClass(minInterval, this.statisticsBand.getMaximum());

        histogramClasses.add(histogramClass);

    }

    @Override

    public void addValue(Number value) {

       ((DefaultHistogramBand)histogramBand).addValue(value.doubleValue());

    }

    @Override

    public void post() {

        // do nothing

    }

    @Override

    public Object getResult() {

        return histogramBand;

    }

}