AS3 handy weighted random & rounding functions with decimal/floating point precision

Like a lot of the "improvements" Adobe made to Actionscript with AS3, the Math.random() function is now a pain in the ass. It only generates a floating point number between 0 and 1 so 99% of the time, you need a few lines of code to get your random on.
With time saving in mind, I've written this weighted random function which makes beautiful randomness a lot handier to implement. For best results throw this in a class package and include it in every project.
Here it comes...



Please see right hand pane before copying my code >>

function round(num:Number, precision:int):Number{
   var decimal:Number = Math.pow(10, precision);
   return Math.round(decimal* num) / decimal;
}

function rand(to:Number, from=0, decimalPlaces=0, weightedRange=0, weightStrength=0):Number{
   var ret
   if(to == from){return(to);}
 
   if(weightedRange && Math.random()<=weightStrength){
      ret = round( Math.random()*(weightedRange[1]-weightedRange[0]) + weightedRange[0], decimalPlaces )
   }else{
      ret = round( Math.random()*(to-from)+from, decimalPlaces )
   }
   return(ret)
}

//USAGE:
rand(100)                   //return random number 0-100 INCLUSIVE
rand(10, -5)                //return random number between -5 and 10
rand(10, -5, 2)             //return random number between -5.00 and 10.00
rand(10, 6, 0, [0,5], 0.9)  //90% chance of returning number between 0-5, 10% chance of returning number between 6-10