You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
124 lines
3.9 KiB
Matlab
124 lines
3.9 KiB
Matlab
function word_indices = processEmail(email_contents)
|
|
%PROCESSEMAIL preprocesses a the body of an email and
|
|
%returns a list of word_indices
|
|
% word_indices = PROCESSEMAIL(email_contents) preprocesses
|
|
% the body of an email and returns a list of indices of the
|
|
% words contained in the email.
|
|
%
|
|
|
|
% Load Vocabulary
|
|
vocabList = getVocabList();
|
|
|
|
% Init return value
|
|
word_indices = [];
|
|
|
|
% ========================== Preprocess Email ===========================
|
|
|
|
% Find the Headers ( \n\n and remove )
|
|
% Uncomment the following lines if you are working with raw emails with the
|
|
% full headers
|
|
|
|
% hdrstart = strfind(email_contents, ([char(10) char(10)]));
|
|
% email_contents = email_contents(hdrstart(1):end);
|
|
|
|
% Lower case
|
|
email_contents = lower(email_contents);
|
|
|
|
% Strip all HTML
|
|
% Looks for any expression that starts with < and ends with > and replace
|
|
% and does not have any < or > in the tag it with a space
|
|
email_contents = regexprep(email_contents, '<[^<>]+>', ' ');
|
|
|
|
% Handle Numbers
|
|
% Look for one or more characters between 0-9
|
|
email_contents = regexprep(email_contents, '[0-9]+', 'number');
|
|
|
|
% Handle URLS
|
|
% Look for strings starting with http:// or https://
|
|
email_contents = regexprep(email_contents, ...
|
|
'(http|https)://[^\s]*', 'httpaddr');
|
|
|
|
% Handle Email Addresses
|
|
% Look for strings with @ in the middle
|
|
email_contents = regexprep(email_contents, '[^\s]+@[^\s]+', 'emailaddr');
|
|
|
|
% Handle $ sign
|
|
email_contents = regexprep(email_contents, '[$]+', 'dollar');
|
|
|
|
|
|
% ========================== Tokenize Email ===========================
|
|
|
|
% Output the email to screen as well
|
|
fprintf('\n==== Processed Email ====\n\n');
|
|
|
|
% Process file
|
|
l = 0;
|
|
|
|
while ~isempty(email_contents)
|
|
|
|
% Tokenize and also get rid of any punctuation
|
|
[str, email_contents] = ...
|
|
strtok(email_contents, ...
|
|
[' @$/#.-:&*+=[]?!(){},''">_<;%' char(10) char(13)]);
|
|
|
|
% Remove any non alphanumeric characters
|
|
str = regexprep(str, '[^a-zA-Z0-9]', '');
|
|
|
|
% Stem the word
|
|
% (the porterStemmer sometimes has issues, so we use a try catch block)
|
|
try str = porterStemmer(strtrim(str));
|
|
catch str = ''; continue;
|
|
end;
|
|
|
|
% Skip the word if it is too short
|
|
if length(str) < 1
|
|
continue;
|
|
end
|
|
|
|
% Look up the word in the dictionary and add to word_indices if
|
|
% found
|
|
% ====================== YOUR CODE HERE ======================
|
|
% Instructions: Fill in this function to add the index of str to
|
|
% word_indices if it is in the vocabulary. At this point
|
|
% of the code, you have a stemmed word from the email in
|
|
% the variable str. You should look up str in the
|
|
% vocabulary list (vocabList). If a match exists, you
|
|
% should add the index of the word to the word_indices
|
|
% vector. Concretely, if str = 'action', then you should
|
|
% look up the vocabulary list to find where in vocabList
|
|
% 'action' appears. For example, if vocabList{18} =
|
|
% 'action', then, you should add 18 to the word_indices
|
|
% vector (e.g., word_indices = [word_indices ; 18]; ).
|
|
%
|
|
% Note: vocabList{idx} returns a the word with index idx in the
|
|
% vocabulary list.
|
|
%
|
|
% Note: You can use strcmp(str1, str2) to compare two strings (str1 and
|
|
% str2). It will return 1 only if the two strings are equivalent.
|
|
%
|
|
|
|
for idx = 1:length(vocabList)
|
|
if strcmp(str, vocabList{idx})
|
|
word_indices = [word_indices ; idx];
|
|
break;
|
|
end
|
|
end
|
|
|
|
% =============================================================
|
|
|
|
|
|
% Print to screen, ensuring that the output lines are not too long
|
|
if (l + length(str) + 1) > 78
|
|
fprintf('\n');
|
|
l = 0;
|
|
end
|
|
fprintf('%s ', str);
|
|
l = l + length(str) + 1;
|
|
|
|
end
|
|
|
|
% Print footer
|
|
fprintf('\n\n=========================\n');
|
|
|
|
end
|