ST 590G -- Computation for Data Analysis

  Fourth Assignment -- due Thursday, 24 November 2011

  The Federalist Papers are pamphlets published in support of the
  US Constitution and are often cited as capturing the original
  intent of the Founding Fathers.  Files with these papers are 
  available at the sites
   http://www.foundingfathers.info/federalistpapers/fedxx.htm
  where xx takes values from 01 to 85. (Note there are two versions
  of 70: 'fed70a' and 'fed70b' -- choose one.)
   * or * (note change below)
   http://thomas.loc.gov/home/histdox/fed_xx.html
  where again xx takes values 01 to 85.  (Note that this site has
  the second version of #70, as the file is 'fed_70-2.html')
   * or * (a third site)
   http://www.constitution.org/fed/federaxx.htm
  where xx takes values 01 to 85.
   * or * (a fourth site)
   http://www.let.rug.nl/usa/D/1776-1800/federalist/fedxx.htm
  where xx takes values 01 to 85.  (Same two versions as with the
  'FoundingFathers' site.  Note the country of this host.)

  Among historians, the general agreement is that
   John Jay wrote 2,3,4,5, and 64;
   James Madison wrote 10, 14, 37, 38, ..., 48;
   no one is sure about 18, 19, 20, 49, 50, ... 58, 62, 63
   and the others were written by Alexander Hamilton.

  Statisticians Mosteller and Wallace did an extensive analysis of word
  frequencies to determine who wrote those other 15 papers.  Your task is
  to gather the data to replicate that task.

  The steps:
  1) Read each file and strip out the html code.
  2) Make a dataset of the words and compute the frequencies of all of
  the words.
  3) Find the word frequencies of the words used by Mosteller & Wallace.
  Their list is given in 'mwwords.dat' -- the hint is 'merge.'
  (Note: treat adverbial/adjectival or plural forms as the same word: 
  "CONSIDERABLY"="CONSIDERABLE", "INNOVATIONS" = "INNOVATION", 
  "VIGOROUS" = "VIGOR", "MATTERS" = "MATTER", "WORKS" = "WORK".)
  4) Create one dataset with word frequencies for the papers with known
  authorship.  Include here all of the (14) Madison papers, and at least
  as many Hamilton papers.  (Use at least 14 of the Hamilton papers;
  use all of them if you want.  You can choose to include the Jay papers
  or just delete them from the analysis.)  Include a variable indicating
  the author.

  5) Create a second dataset with the 15 papers where the authorship 
  is not certain.  Include a variable 'author' with missing values.