Moving course1 to course1 subdir.

machine_learning/course1/mlclass-ex6-008/mlclass-ex6/emailFeatures.m

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+function x = emailFeatures(word_indices)
+%EMAILFEATURES takes in a word_indices vector and produces a feature vector
+%from the word indices
+%   x = EMAILFEATURES(word_indices) takes in a word_indices vector and 
+%   produces a feature vector from the word indices. 
+
+% Total number of words in the dictionary
+n = 1899;
+
+% You need to return the following variables correctly.
+x = zeros(n, 1);
+
+% ====================== YOUR CODE HERE ======================
+% Instructions: Fill in this function to return a feature vector for the
+%               given email (word_indices). To help make it easier to 
+%               process the emails, we have have already pre-processed each
+%               email and converted each word in the email into an index in
+%               a fixed dictionary (of 1899 words). The variable
+%               word_indices contains the list of indices of the words
+%               which occur in one email.
+% 
+%               Concretely, if an email has the text:
+%
+%                  The quick brown fox jumped over the lazy dog.
+%
+%               Then, the word_indices vector for this text might look 
+%               like:
+%               
+%                   60  100   33   44   10     53  60  58   5
+%
+%               where, we have mapped each word onto a number, for example:
+%
+%                   the   -- 60
+%                   quick -- 100
+%                   ...
+%
+%              (note: the above numbers are just an example and are not the
+%               actual mappings).
+%
+%              Your task is take one such word_indices vector and construct
+%              a binary feature vector that indicates whether a particular
+%              word occurs in the email. That is, x(i) = 1 when word i
+%              is present in the email. Concretely, if the word 'the' (say,
+%              index 60) appears in the email, then x(60) = 1. The feature
+%              vector should look like:
+%
+%              x = [ 0 0 0 0 1 0 0 0 ... 0 0 0 0 1 ... 0 0 0 1 0 ..];
+%
+%
+
+for i=1:length(word_indices)
+	x(word_indices(i)) |= 1;
+end
+
+% =========================================================================
+    
+
+end