title: Understanding the syntax for Column vs Row indexing in R
body: <p>I'm a bit confused on the filtering scheme on an R data frame.</p>
  
  <p>For example, let's say we have the following data frame titled <code>dframe</code>:</p>
  
  <pre><code>&gt; str(dframe)
  'data.frame':   143 obs. of  3 variables:
   $ Year     : int  1999 2005 2007 2008 2009 2010 2005 2006 2007 2008 ...
   $ Name     : Factor w/ 18 levels "AADAM","AADEN",..: 1 1 2 2 2 2 3 3 3 3 ...
   $ Frequency: int  5 6 10 34 38 12 10 6 10 5 ...
  </code></pre>
  
  <p>Now if I want to filter <code>dframe</code> where the values of Name is of "AADAM", the proper filter is:
  <code>dframe[dframe$Name=="AADAM",]</code></p>
  
  <p>The part where I'm confused is why the comma doesn't come first. Why isn't it this: <code>dframe[,dframe$Name=="AARUSH"]</code></p>