One thing I&#x27;d add to the section on &quot;Coming from another language&quot; [0] is a brief introduction to non-standard-evaluation. Hadley Wickham&#x27;s Advanced R (free to read on the Web) has a nice section on it:<p><a href="http:&#x2F;&#x2F;adv-r.had.co.nz&#x2F;Computing-on-the-language.html" rel="nofollow">http:&#x2F;&#x2F;adv-r.had.co.nz&#x2F;Computing-on-the-language.html</a><p>NSE is what allows these two statements to both work:<p><pre><code>    library(&#x27;ggplot2&#x27;)
</code></pre>
and:<p><pre><code>    library(ggplot2)
</code></pre>
It&#x27;s a relatively minor thing but it helps to explain some of the &quot;magic&quot; (Wickham&#x27;s chapter opens with an example of how `plot()` magically knows what to label the axes) of R and might explain some of the baffling inconsistencies you might find in code out in the wild.<p>[0] <a href="http:&#x2F;&#x2F;www.burns-stat.com&#x2F;documents&#x2F;tutorials&#x2F;impatient-r&#x2F;r-coming-programming-languages&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.burns-stat.com&#x2F;documents&#x2F;tutorials&#x2F;impatient-r&#x2F;r-...</a>