/** 
 * The Grapher.js file contains the 'main' method to the Grapher package.  It is a package that
 * provides the necessary API to plot several 2-dimensional functions on a graph on 
 * any W3C-standards compliant browser capable of rendering 
 * dynamic HTML and that supports the 'innerHTML' attribute.  
 * It can render several functions without erasing the previous
 * plots, in order to facilitate visual comparison. 
 * Author: Christopher M. Balz.
 * Date: September 14, 2001.
 * Copyright Christopher M. Balz, 2001.  All rights reserved.
 */