title: How to convert a table in a matrix in KNIME?
body: <p>Is it possible and if so, how to convert a table to a matrix?</p>
  <p>My output table is structured as follows:</p>
  <pre><code>rowid   user   item   value
    0      x      A      10
    1      x      B      15
    2      x      C      0
    3      y      A      12
    4      y      B      17
    5      y      C      25 
  </code></pre>
  <p>My goal is to create a matrix in the following form:</p>
  <pre><code>rowid    A    B    C
    x      10   15   0
    y      12   17   25
  </code></pre>