Java Array Normalize normalizeL2(double[] a)

Description

L2 normalization

License

Apache License

Parameter

Parameter	Description
a	a parameter

Declaration

public static void normalizeL2(double[] a) 

Method Source Code

//package com.java2s;
/**/*from  w ww. j a  va 2s  .c  o  m*/
 * 
 *    Copyright 2017 Florian Erhard
 *
 *   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.
 * 
 */

public class Main {
    /**
     * L2 normalization
     * @param a
     */
    public static void normalizeL2(double[] a) {
        double sum = 0;
        for (double x : a)
            sum += x * x;
        sum = Math.sqrt(sum);
        if (sum == 0)
            for (int i = 0; i < a.length; i++)
                a[i] = 1 / a.length;
        else
            for (int i = 0; i < a.length; i++)
                a[i] /= sum;
    }
}

Related

1. normalizeHeightMapCopy(float heightMap[])
2. normalizeHistogram(int[] h)
3. normalizeHistogram(int[] hist)
4. normalizeHistogramToBase(int[] hist, double base)
5. normalizeInnerPointDistanceMax(double[][] distances, double maxDist)
6. normalizeL2(double[] histogram)
7. normalizeLengthInPlace(double[] in)
8. normalizeLog(double[] logs)
9. normalizeMatrix(double[][] M)