title: scikit-learn TfidfVectorizer meaning?
body: <p>I was reading about TfidfVectorizer <a href="http://stanford.edu/~rjweiss/public_html/IRiSS2013/text2/notebooks/tfidf.html" rel="noreferrer">implementation</a> of scikit-learn, i don´t understand what´s the output of the method, for example:</p>
  
  <pre><code>new_docs = ['He watches basketball and baseball', 'Julie likes to play basketball', 'Jane loves to play baseball']
  new_term_freq_matrix = tfidf_vectorizer.transform(new_docs)
  print tfidf_vectorizer.vocabulary_
  print new_term_freq_matrix.todense()
  </code></pre>
  
  <p>output:</p>
  
  <pre><code>{u'me': 8, u'basketball': 1, u'julie': 4, u'baseball': 0, u'likes': 5, u'loves': 7, u'jane': 3, u'linda': 6, u'more': 9, u'than': 10, u'he': 2}
  [[ 0.57735027  0.57735027  0.57735027  0.          0.          0.          0.
     0.          0.          0.          0.        ]
   [ 0.          0.68091856  0.          0.          0.51785612  0.51785612
     0.          0.          0.          0.          0.        ]
   [ 0.62276601  0.          0.          0.62276601  0.          0.          0.
     0.4736296   0.          0.          0.        ]]
  </code></pre>
  
  <p>What is?(e.g.: u'me': 8 ):</p>
  
  <pre><code>{u'me': 8, u'basketball': 1, u'julie': 4, u'baseball': 0, u'likes': 5, u'loves': 7, u'jane': 3, u'linda': 6, u'more': 9, u'than': 10, u'he': 2}
  </code></pre>
  
  <p>is this a matrix or just a vector?, i can´t understand what´s telling me the output:</p>
  
  <pre><code>[[ 0.57735027  0.57735027  0.57735027  0.          0.          0.          0.
     0.          0.          0.          0.        ]
   [ 0.          0.68091856  0.          0.          0.51785612  0.51785612
     0.          0.          0.          0.          0.        ]
   [ 0.62276601  0.          0.          0.62276601  0.          0.          0.
     0.4736296   0.          0.          0.        ]]
  </code></pre>
  
  <p>Could anybody explain me in more detail these outputs?</p>
  
  <p>Thanks!</p>