title: Create Similarity Matrix
body: <p>I have a matrix that looks like the following:</p>
  
  <pre><code>col_1 col_2 value
  
   A      B     2.1
  
   A      C     1.3
  
   B      C     4.6
  
   A      D     1.4
  
  ....
  </code></pre>
  
  <p>I would like to get a similarity matrix:</p>
  
  <pre><code>    A    B    C   D
  
  A    X   2.1  1.3  1.4
  
  B    2.1  X   4.6   ...
  
  C    ...  ...  X    ...
  
  D    ...  ... ...    X
  </code></pre>
  
  <p>So the row and the column names are A,B,C,D and the it takes the value from the third column and adds it to the matrix
  The problem is also that the original matrix has a length of approximately 10 000 rows.</p>