title: Plot occurances on a timeseries with Gnuplot
body: <p>I'm trying to plot occurrences of an event on top of some other graphs of how much time a process took to see if there is a correlation but I can't figure out how to make gnuplot sum the data properly. Since the data is not numerical i'm having trouble applying material related to plotting histograms. Here is my data:</p>
  
  <pre><code>"2012-05-15 08:12:49","foo"
  "2012-05-15 08:13:01","foo"
  "2012-05-15 08:13:58","foo"
  "2012-05-15 08:14:03","foo"
  "2012-05-15 08:14:10","foo"
  "2012-05-15 08:14:17","foo"
  "2012-05-15 08:14:33","foo"
  "2012-05-15 08:14:35","foo"
  
  ...
  
  "2012-05-15 10:31:51","foo"
  "2012-05-15 10:32:02","foo"
  "2012-05-15 10:32:03","foo"
  "2012-05-15 10:32:07","foo"
  "2012-05-15 10:32:09","foo"
  "2012-05-15 10:32:15","foo"
  </code></pre>
  
  <p>This is extent of the data file, I'd like to have a graph with a line that represents how many events happened at that time</p>
  
  <p>(so I could overlay this onto my other plot that has time of the processing plotted)</p>
  
  <p>Is this possible?</p>
  
  <p><strong>Edit:</strong> I've tried several combinations of options so far, but none have yielded any readable graph, <a href="http://pastie.org/5475243" rel="nofollow">here</a> is the gnuplot file i'm using, <code>type1.csv</code> and <code>type2.csv</code> are from the graph i'm overlaying. small_report.csv is a 1000 row extract of the 'occurrence' data.</p>