code: private static double[] numberListToDoubleArray(List<Number> listOfNumbers) {
  		double[] arrayOfDoubles	= new double[listOfNumbers.size()];
  		for(int i=0; i<arrayOfDoubles.length; i++) {
  			arrayOfDoubles[i] = listOfNumbers.get(i).doubleValue();
  		}
  		return arrayOfDoubles;
  	}
docs: Convert a list of numbers to an array of doubles.
  
  @param listOfNumbers A list of numbers.
  @return A corresponding array of doubles executing <code>doubleValue()</code> on each element.