title: Remove rows with less than a certain number of non-blank cells
body: <p>I need to remove all the rows from the dataframe below with less than 2 numbers. That means that only the first row should remain.</p>
  
  <pre><code>a&lt;-c(1,"")
  b&lt;-c(2,"")
  AB&lt;-data.frame(a,b)
  </code></pre>