@Override public double valueToAngle(double value){
  double range=this.upperBound - this.lowerBound;
  double unit=this.extent / range;
  return this.startAngle + unit * (value - this.lowerBound);
}

@ Override public double valueToAngle ( double value ) { double range = this . upperBound - this . lowerBound ; double unit = this . extent / range ; return this . startAngle + unit * ( value - this . lowerBound ) ; }
converts a data value to an angle against this scale .
