docs: public void reverse() {
  	// overridden for performance only.
  	double tmp;
  	int limit=size/2;
  	int j=size-1;
  
  	double[] theElements = elements;
  	for (int i=0; i<limit;) { //swap
  		tmp=theElements[i];
  		theElements[i++]=theElements[j];
  		theElements[j--]=tmp;
  	}
  }