This is a test

mydata$ageT1[ is.na(mydata$ageT1) ] <- -999
mydata$ageT2[ is.na(mydata$ageT2) ] <- -999

      /* Initialize some variables using C style comments
           $a - contains a-coefficient
           $b - contains b-coefficient
           $x - value we are evaluating
           $y - result from evaluating equation */
      $a = 1; $b = 2; $x = 1;
      $y = $a * $x + $b;
      if ( $y < 5 )                // C++ style comment, check if y<5
      {
              # Shell style comment, display something when y<5
              echo "Guess what?  y is less than 5!";
      }