title: How to create pulsating value from 0..1..0..1..0 etc for a given duration?
body: <p>I'm working on some code where I have a <code>Time</code> object with a member <code>time</code>. <code>Time.time</code> gives
  me the time since my application started in seconds (float value).  Now I want to create a pulsating value between 0 and 1 and then from 1 to 0 again, which continues doing thins untill the application stops.</p>
  
  <p>I was thinking to use sin() but don't know what to pass to it as paramters to create this pulsing value. </p>
  
  <p>How would I create this pulsating value?</p>
  
  <p>Kind regards,
  Pollux</p>