title: Aggregate & Total in R
body: <p>Data:</p>
  
  <pre><code>ProjectA,12
  ProjectB,24
  ProjectA,15
  </code></pre>
  
  <p>I'd like to calculate the sum for every project and then total so that the result is:</p>
  
  <pre><code>Project    Sum
  ProjectA    27
  ProjectB    24
  Total       51
  </code></pre>
  
  <p>Is there a function that can do this? Right now I need to do 2 calls:</p>
  
  <pre><code>paste('Size of all projects: ', sum(projects$size))
  aggregate(projects$size, by=list(projects$name), sum)
  </code></pre>