VectorUtil.java

/*
 * Artificial Intelligence for Humans
 * Volume 1: Fundamental Algorithms
 * Java Version
 * http://www.aifh.org
 * http://www.jeffheaton.com
 *
 * Code repository:
 * https://github.com/jeffheaton/aifh

 * Copyright 2013 by Jeff Heaton
 *
 * 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.
 *
 * For more information on Heaton Research copyrights, licenses
 * and trademarks visit:
 * http://www.heatonresearch.com/copyright
 */

package com.heatonresearch.aifh.general;

/**
 * Some vector utilities.
 */
public final class VectorUtil {

    /**
     * Private constructor.
     */
    private VectorUtil() {

    }

    /**
     * Return the index that has the max value.
     *
     * @param a The vector.
     * @return The index.
     */
    public static int maxIndex(final double[] a) {
        int result = -1;
        double max = Double.NEGATIVE_INFINITY;

        for (int i = 0; i < a.length; i++) {
            if (a[i] > max) {
                max = a[i];
                result = i;
            }
        }

        return result;
    }
}