title: How to export R matrix object to .txt file
body: <p>I have a R object say:</p>
  
  <pre><code>mat &lt;- matrix(1:100,nrow=20)
  </code></pre>
  
  <p>I want to send this matrix to .txt file so that the exported .txt file contains 20 rows and 5 columns. Is there easy way to do this?</p>
  
  <p>Thanks in advance,</p>