title: How to plot binary data via a dotplot?
body: <p>I have a dataset that includes presence absence of a variable based on hour and day. I'd like to plot presence (i.e., just &quot;Y&quot;) by hour and day with day on the x and hour on the y axis. I'm just not good at this stuff and it's giving me trouble. See example data:</p>
  <pre><code>df &lt;- data.frame(&quot;day&quot;= c(1, 1, 1, 2, 2, 2, 3, 3, 3),&quot;hour&quot; = c(1, 2, 3, 1, 2, 2, 1, 2, 3),&quot;a&quot; = c(&quot;Y&quot;, &quot;Y&quot;, &quot;N&quot;, &quot;N&quot;, &quot;N&quot;, &quot;Y&quot;, &quot;N&quot;, &quot;N&quot;, &quot;Y&quot;), &quot;b&quot; = c(&quot;N&quot;, &quot;N&quot;, &quot;Y&quot;, &quot;N&quot;, &quot;Y&quot;, &quot;Y&quot;, &quot;Y&quot;, &quot;Y&quot;, &quot;Y&quot;))
  </code></pre>
  <p>Would love any suggestions.</p>