title: Why are these numbers not equal?
body: <p>The following code is obviously wrong.  What's the problem?</p>
  
  <pre><code>i &lt;- 0.1
  i &lt;- i + 0.05
  i
  ## [1] 0.15
  if(i==0.15) cat("i equals 0.15") else cat("i does not equal 0.15")
  ## i does not equal 0.15
  </code></pre>