title: How to create a time scatterplot with R?
body: <p>The data are a series of dates and times.</p>
  
  <pre><code>date time
  2010-01-01 09:04:43
  2010-01-01 10:53:59
  2010-01-01 10:57:18
  2010-01-01 10:59:30
  2010-01-01 11:00:44
  …
  </code></pre>
  
  <p>My goal was to represent a scatterplot with the date on the horizontal axis (x) and the time on the vertical axis (y). I guess I could also add a color intensity if there are more than one time for the same date. </p>
  
  <p>It was quite easy to create an histogram of dates.</p>
  
  <pre><code>mydata &lt;- read.table("mydata.txt", header=TRUE, sep=" ")
  mydatahist &lt;- hist(as.Date(mydata$day), breaks = "weeks", freq=TRUE, plot=FALSE)
  barplot(mydatahist$counts, border=NA, col="#ccaaaa")
  </code></pre>
  
  <ol>
  <li>I haven't figured out yet how to create a scatterplot where the axis are date and/or time. </li>
  <li>I would like also to be able to have axis not necessary with linear dates YYYY-MM-DD, but also based on months such as MM-DD (so different years accumulate), or even with a rotation on weeks.</li>
  </ol>
  
  <p>Any help, RTFM URI slapping or hints is welcome.</p>