title: acf function in R return values
body: <p>I would like to compute a simple <code>acf</code> in R. For example, consider:</p>
  
  <pre><code>v = acf(1:10, plot=F)
  </code></pre>
  
  <p><code>v</code> now contains an element called <code>lag</code> which is a 3-dim array containing the last used in the estimation. How come this array is 3 dimensional and not simply 1 dimensional? I am asking because I would like to foresee exactly what will be in each dimension depending on the use-case.</p>