docs: public float remove(int idx)	{
  		float ret = -1f;
  		int p = Arrays.binarySearch(index,0,length, idx);
  		if (p >= 0)	{
  			System.arraycopy(data, p+1, data, p, length-p-1);
  			System.arraycopy(index, p+1, index, p, length-p-1);
  			length--;
  		}else{
  			System.err.println("error");
  		}
  		return ret;
  	}