code: public static long symmetric(double v)
  	{
  		final long rva = Math.round(Math.abs(v));
  		
  		return v >= 0 ? rva : -rva;
  	}
docs: Symmetric rounding around zero. I.e. rounding towards/away from zero rather than rounding
  towards floor(v) / ceil(v).
  
  For all v:
  -symmetric(v) == symmetric(-v)
  
  @param v input value
  @return rounded value