title: Split data into two training and one test sets
body: <p>How can we split data int two training sets and one testing set using R?</p>
  
  <p>I tried this, but I want to split train into two training sets:</p>
  
  <pre><code>set.seed(770)
  sample &lt;- sample.int(n = nrow(datazoo), size = floor(0.75*nrow(datazoo)), replace = F)
  train &lt;- datazoo[sample, ]
  test  &lt;- datazoo[-sample, ]
  </code></pre>
  
  <p>Thanks</p>