org.mrgeo.aggregators.MinAvgPairAggregator.java Source code

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Here is the source code for org.mrgeo.aggregators.MinAvgPairAggregator.java

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/*
 * Copyright 2009-2016 DigitalGlobe, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and limitations under the License.
 *
 */

/**
 * 
 */
package org.mrgeo.aggregators;

import org.apache.commons.lang3.NotImplementedException;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;

/**
 * Uses the minimum average pixel value calculated for 
 * each row and column and diagonal pair.  Pairs with
 * a "no data" value will be excluded.
 */
public class MinAvgPairAggregator implements Aggregator {

    @Override
    public double aggregate(double[] values, double nodata) {
        boolean data0 = Double.compare(values[0], nodata) != 0;
        boolean data1 = Double.compare(values[1], nodata) != 0;
        boolean data2 = Double.compare(values[2], nodata) != 0;
        boolean data3 = Double.compare(values[3], nodata) != 0;

        Collection<Double> averages = new ArrayList<Double>();
        if (data0 && data1)
            averages.add(Double.valueOf((values[0] + values[1]) / 2));
        if (data0 && data2)
            averages.add(Double.valueOf((values[0] + values[2]) / 2));
        if (data0 && data3)
            averages.add(Double.valueOf((values[0] + values[3]) / 2));
        if (data1 && data2)
            averages.add(Double.valueOf((values[1] + values[2]) / 2));
        if (data1 && data3)
            averages.add(Double.valueOf((values[1] + values[3]) / 2));
        if (data2 && data3)
            averages.add(Double.valueOf((values[2] + values[3]) / 2));

        return (averages.isEmpty()) ? nodata : Collections.min(averages).doubleValue();
    }

    @Override
    public float aggregate(float[] values, float nodata) {
        boolean data0 = Float.compare(values[0], nodata) != 0;
        boolean data1 = Float.compare(values[1], nodata) != 0;
        boolean data2 = Float.compare(values[2], nodata) != 0;
        boolean data3 = Float.compare(values[3], nodata) != 0;

        Collection<Float> averages = new ArrayList<Float>();
        if (data0 && data1)
            averages.add(Float.valueOf((values[0] + values[1]) / 2));
        if (data0 && data2)
            averages.add(Float.valueOf((values[0] + values[2]) / 2));
        if (data0 && data3)
            averages.add(Float.valueOf((values[0] + values[3]) / 2));
        if (data1 && data2)
            averages.add(Float.valueOf((values[1] + values[2]) / 2));
        if (data1 && data3)
            averages.add(Float.valueOf((values[1] + values[3]) / 2));
        if (data2 && data3)
            averages.add(Float.valueOf((values[2] + values[3]) / 2));

        return (averages.isEmpty()) ? nodata : Collections.min(averages).floatValue();
    }

    @Override
    public int aggregate(int[] values, int nodata) {
        boolean data0 = values[0] != nodata;
        boolean data1 = values[1] != nodata;
        boolean data2 = values[2] != nodata;
        boolean data3 = values[3] != nodata;

        Collection<Integer> averages = new ArrayList<Integer>();
        if (data0 && data1)
            averages.add(Integer.valueOf((values[0] + values[1]) / 2));
        if (data0 && data2)
            averages.add(Integer.valueOf((values[0] + values[2]) / 2));
        if (data0 && data3)
            averages.add(Integer.valueOf((values[0] + values[3]) / 2));
        if (data1 && data2)
            averages.add(Integer.valueOf((values[1] + values[2]) / 2));
        if (data1 && data3)
            averages.add(Integer.valueOf((values[1] + values[3]) / 2));
        if (data2 && data3)
            averages.add(Integer.valueOf((values[2] + values[3]) / 2));

        return (averages.isEmpty()) ? nodata : Collections.min(averages).intValue();
    }

    @Override
    public double aggregate(double[][] values, double weightx, double weighty, double nodata) {
        throw new NotImplementedException("Not yet implemented");
    }

    @Override
    public float aggregate(float[][] values, double weightx, double weighty, float nodata) {
        throw new NotImplementedException("Not yet implemented");
    }

    @Override
    public int aggregate(final int[][] values, final double weightx, final double weighty, final int nodata) {
        throw new NotImplementedException("Not yet implemented");
    }

}