title: How to compute the conditional probability in R?
body: <p>Let's suppose I have these two vectors:</p>
  
  <pre><code>x = rnorm(20)
  y = rnorm(20)
  </code></pre>
  
  <p>I want to compute the probability that <code>y &gt; 0</code> given that <code>x &gt; 0</code>. 
  In other words, I want the frequency that my <code>y &gt; 0</code> when <code>x &gt; 0</code>.
  Can anyone show me how to code this in R?</p>