title: How to initialize a vector of TRUE in R?
body: <p>Let's say I want to initialize a vector containing only <code>TRUE</code>, of a length <code>n</code>, where <code>n</code> is a positive integer.</p>
  
  <p>Obviously, I can do <code>!logical(n)</code>, as well as <code>rep(TRUE,n)</code>.</p>
  
  <p>However, I would like to know which of them is faster, and whether there are other (faster) alternatives.</p>