* @file functions.h
 * @brief Class containing extra functions which are not available in the
 * default c++ libraries.
 * @license
 * 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.
 * Copyright (C) 2007-2011 Jos de Jong, http://www.speqmath.com
 * @author 	Jos de Jong, <wjosdejong@gmail.com>
 * @date	2007-12-22, updated 2012-02-06


using namespace std;

double factorial(double value);
double sign(double value);