title: Hiding the R code in Rmarkdown/knit and just showing the results
body: <p>In my R Markdown documents, I sometimes want to just generate a report without showing the actual code (specially when I send it to my boss). How can I hide the R code and just show the graph and results?</p>
  
  <p>For example:</p>
  
  <pre><code>---
  output: html_document
  ---
  
  ```{r fig.width=16, fig.height=6}
  plot(cars)
  ```
  </code></pre>
  
  <p>This shows both the commands and the plot. How can I remove the commands from my HTML report?</p>