File-Name:       comparative_word_cloud.R           
Date:            2012-03-01                              
Author:          Winter Mason
Email:           [email protected]                                   
Purpose:         Attempt to improve on Drew Conway's word-cloud
Packages Used:   tm, ggplot2  
Input:		 sourcedir: directory that contains two text files to be compared
		 imgname: the name of the output image file
		 add.stops: a list of words to ignore in the text
		 nwords: the maximum number of most frequent words to plot
		 imgwidth,imgheight: dimensions of the resulting image
		 mintext,maxtext: the range of word sizes in the plot
Output File:     word_cloud.pdf

Copyright (c) 2012, under the Simplified BSD License.  
For more information on FreeBSD see: http://www.opensource.org/licenses/bsd-license.php
All rights reserved.                                                         

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Example usage to recreate the Obama-Palin word cloud from the blog post:

source('comparative_word_cloud.R')
comparative.word.cloud("data/",imgname="fig/word_cloud.png",add.stops=c("applause"),nwords=100)