Here you can find the source of dotProduct(double x1, double y1, double x2, double y2)
public final static double dotProduct(double x1, double y1, double x2, double y2)
//package com.java2s; /*/* w ww . j a v a 2 s .c o m*/ * Copyright 2009-2013 by The Regents of the University of California * 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 from * * 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 { public final static double dotProduct(double x1, double y1, double x2, double y2) { return x1 * x2 + y1 * y2; } }