com.opengamma.maths.lowlevelapi.functions.utilities.Reverse.java Source code

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Here is the source code for com.opengamma.maths.lowlevelapi.functions.utilities.Reverse.java

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/**
 * Copyright (C) 2011 - present by OpenGamma Inc. and the OpenGamma group of companies
 *
 * Please see distribution for license.
 */
package com.opengamma.maths.lowlevelapi.functions.utilities;

import java.util.Arrays;

import org.apache.commons.lang.Validate;

/**
 * Reverses Vectors
 */
public class Reverse {

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     */
    public static void inPlace(int[] v1) {
        Validate.notNull(v1);
        int tmp;
        final int half = v1.length / 2;
        final int len = v1.length - 1;
        for (int i = 0; i < half; i++) {
            tmp = v1[len - i];
            v1[len - i] = v1[i];
            v1[i] = tmp;
        }
    }

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     */
    public static void inPlace(long[] v1) {
        Validate.notNull(v1);
        long tmp;
        final int half = v1.length / 2;
        final int len = v1.length - 1;
        for (int i = 0; i < half; i++) {
            tmp = v1[len - i];
            v1[len - i] = v1[i];
            v1[i] = tmp;
        }
    }

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     */
    public static void inPlace(float[] v1) {
        Validate.notNull(v1);
        float tmp;
        final int half = v1.length / 2;
        final int len = v1.length - 1;
        for (int i = 0; i < half; i++) {
            tmp = v1[len - i];
            v1[len - i] = v1[i];
            v1[i] = tmp;
        }
    }

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     */
    public static void inPlace(double[] v1) {
        Validate.notNull(v1);
        double tmp;
        final int half = v1.length / 2;
        final int len = v1.length - 1;
        for (int i = 0; i < half; i++) {
            tmp = v1[len - i];
            v1[len - i] = v1[i];
            v1[i] = tmp;
        }
    }

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     * @return r a reversed copy of v1
     */
    public static int[] stateless(int[] v1) {
        Validate.notNull(v1);
        int[] r = Arrays.copyOf(v1, v1.length);
        inPlace(r);
        return r;
    }

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     * @return r a reversed copy of v1
     */
    public static long[] stateless(long[] v1) {
        Validate.notNull(v1);
        long[] r = Arrays.copyOf(v1, v1.length);
        inPlace(r);
        return r;
    }

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     * @return r a reversed copy of v1
     */
    public static float[] stateless(float[] v1) {
        Validate.notNull(v1);
        float[] r = Arrays.copyOf(v1, v1.length);
        inPlace(r);
        return r;
    }

    /**
     * Reverses a vector in place
     * @param v1 the vector to be reversed
     * @return r a reversed copy of v1
     */
    public static double[] stateless(double[] v1) {
        Validate.notNull(v1);
        double[] r = Arrays.copyOf(v1, v1.length);
        inPlace(r);
        return r;
    }

}