title: Adding a new column to matrix error
body: <p>I'm trying to add a new column to existing matrix, but getting warning everytime.</p>
  
  <p>I'm trying this code:</p>
  
  <pre><code>normDisMatrix$newColumn &lt;- labels
  </code></pre>
  
  <p>Getting this message:</p>
  
  <blockquote>
    <p>Warning message: In normDisMatrix$newColumn &lt;- labels : Coercing LHS
    to a list</p>
  </blockquote>
  
  <p>After it, when I check the matrix, it seems null:</p>
  
  <pre><code>dim(normDisMatrix)
  NULL
  </code></pre>
  
  <p><strong>Note:</strong> labels are just vectors which have numbers between 1 and 4.</p>
  
  <p>What can be the problem?</p>