title: How to get the total length of a Row Vector in PARI/GP
body: <p>from the divisors of a certain number, im trying to randomly choose a divisor. </p>
  
  <p>However i am unable to randomly get a number as i could not find any function that can get me the length of a row vector.</p>
  
  <p>example:</p>
  
  <pre><code>temp=divisors(12);
  [1,2,3,4,6,12]
  vecmax(temp); \\will get me 10 instead of 6
  temp[random(vecmax(temp))];
  </code></pre>
  
  <p>Hopefully someone here can help me with this. Thanks! :)</p>