title: Adding missing rows
body: <p>The format of my excel data file is:</p>
  
  <pre><code> day                 value
   01-01-2000 00:00:00    4
   01-01-2000 00:01:00    3
   01-01-2000 00:02:00    1
   01-01-2000 00:04:00    1
  </code></pre>
  
  <p>I open my file with this:</p>
  
  <pre><code>ts = read.csv(file=pathfile, header=TRUE, sep=",")
  </code></pre>
  
  <p>How can I add additional rows with zero number in column “value” into the data frame. Output example:</p>
  
  <pre><code> day                  value
   01-01-2000 00:00:00    4
   01-01-2000 00:01:00    3
   01-01-2000 00:02:00    1
   01-01-2000 00:03:00    0
   01-01-2000 00:04:00    1
  </code></pre>