/// <summary>
/// 构造一个和平台宽度相同的窗口;
/// 看窗口内的数据是否相等;
/// 如果相等，看两边的数据是否满足上升和下降条件;
/// 如果满足则记录位置;
/// 否则窗口滑动
/// </summary>
/// <param name="srclist"></param>
/// <param name="faltwidth"></param>
/// <returns></returns>
private List <FlatInfo> FindFlat(List <double> input_data, int flat_width)
{
if (input_data == null)
{
return(null);
}
if (input_data.Count == 0)
{
return(null);
}
if (flat_width < 2)
{
return(null);
}
if (input_data.Count <= flat_width)
{
return(null);
}
List <FlatInfo> flist = new List <FlatInfo>();
List <double> window = input_data.GetRange(0, flat_width);
for (int i = flat_width - 1; i < input_data.Count; i++)
{
//取平台窗口大小的数据
if (i > flat_width - 1)
{
window.RemoveAt(0);
window.Add(input_data[i]);
}
FlatInfo _flat = MakeFlat(window, input_data, i);
if (_flat != null)
{
flist.Add(_flat);
}
//FlatInfo _positive_flat = MakeFlat(window, input_data, i, true);
//if (_positive_flat != null) flist.Add(_positive_flat);
//FlatInfo _negative_flat = MakeFlat(window, input_data, i, false);
//if (_negative_flat != null) flist.Add(_negative_flat);
}
if (flist.Count <= 0)
{
return(null);
}
return(flist);
}
/// <summary>
/// midpoint filter
/// </summary>
/// <param name="srcData"></param>
/// <param name="FrameSize"></param>
/// <returns></returns>
protected virtual double[] Process(double[] input_data, MedianFilterArgs args)
{
if (input_data == null)
{
return(null);
}
if (args == null)
{
return(null);
}
if (input_data.Length <= args.FrameSize)
{
return(input_data);
}
int _half_window_size = args.FrameSize / 2;
int _flat_width = _half_window_size + 1;
//一次滤波过程中总有半窗口长度的数据未被滤波
//组织用于恢复平台的原始数据
List <double> _input_data_list = input_data.ToList();
_input_data_list.InsertRange(0, this._his_input_nofilting);
_his_input_nofilting = _input_data_list.GetRange(_input_data_list.Count - _half_window_size, _half_window_size);//更新数据偏移
_input_data_list.RemoveRange(_input_data_list.Count - _half_window_size, _half_window_size);
_input_data_list.InsertRange(0, this._his_input_list);
//中值滤波
double[] _mid_data_buf = _midFilter.Process(input_data, args);
if (_mid_data_buf == null)
{
return(null);
}
if (_mid_data_buf.Length <= _flat_width)
{
return(_mid_data_buf);
}
//组织滤波后的数据，数量应该与input_data_list数据一致
List <double> _mid_data_list = _mid_data_buf.ToList();
_mid_data_list.InsertRange(0, this._his_mid_list);
if (_mid_data_list.Count != _input_data_list.Count)
{
return(null);
}
//寻找并处理平台
List <FlatInfo> _flat_list = _flatPro.Process(_mid_data_list.ToArray(), args);
if (_flat_list != null && _flat_list.Count != 0)
{
//用原始数据恢复平台
foreach (FlatInfo fi in _flat_list)
{
_mid_data_list.RemoveRange(fi.StartIndex, fi.FlatWidth);
_mid_data_list.InsertRange(fi.StartIndex, _input_data_list.GetRange(fi.StartIndex, fi.FlatWidth));
}
}
//处理历史数据
_his_mid_list.Clear();
_his_input_list.Clear();
if ((_flat_list == null) || (_flat_list.Count == 0))
{
_his_mid_list.AddRange(_mid_data_list.GetRange(_mid_data_list.Count - (_half_window_size + 2), _half_window_size + 2));
_his_input_list.AddRange(_input_data_list.GetRange(_input_data_list.Count - (_half_window_size + 2), _half_window_size + 2));
_mid_data_list.RemoveRange(_mid_data_list.Count - (_half_window_size + 2), _half_window_size + 2);
}
else
{
FlatInfo _flat_info = _flat_list[_flat_list.Count - 1];
int _end_index = _flat_info.StopIndex + 1;
_his_mid_list.AddRange(_mid_data_list.GetRange(_end_index, _mid_data_list.Count - _end_index));
_his_input_list.AddRange(_input_data_list.GetRange(_end_index, _input_data_list.Count - _end_index));
_mid_data_list.RemoveRange(_end_index, _mid_data_list.Count - _end_index);
}
//for (int i = _mid_data_list.Count - 1; i >= _mid_data_list.Count - _flat_width; i--)
//{
// if (_mid_data_list[i - 1] == _mid_data_list[i])
// {
// this._his_mid_list.Clear();
// this._his_input_list.Clear();
// }
// else
// {
// this._his_mid_list.Clear();
// int count = _mid_data_list.Count - i + 1;
// this._his_mid_list.AddRange(_mid_data_list.GetRange(i - 1, count));
// _mid_data_list.RemoveRange(i - 1, count);
// this._his_input_list.Clear();
// this._his_input_list.AddRange(_input_data_list.GetRange(i - 1, count));
// break;
// }
//}
return(_mid_data_list.ToArray());
}
/// <summary>
/// 查找平台
/// </summary>
/// <param name="window">平台窗口</param>
/// <param name="srclist">源数据</param>
/// <param name="endIndex">源数据中平台窗口最后数据的索引</param>
/// <param name="bPositiveFlat">查找平台类型：正峰平台，负峰平台</param>
/// <returns>平台信息，如果没有则返回null</returns>
//private FlatInfo MakeFlat(List<double> window, List<double> input_data_list, int endIndex, bool bPositiveFlat)
private FlatInfo MakeFlat(List <double> window, List <double> input_data_list, int endIndex)
{
if (window == null)
{
return(null);
}
if (input_data_list == null)
{
return(null);
}
if (input_data_list.Count == 0)
{
return(null);
}
if (window.Count == 0)
{
return(null);
}
if (endIndex >= input_data_list.Count)
{
return(null);
}
if (endIndex < window.Count)
{
return(null);
}
IEnumerable <double> var = from v in window where v == window[0] select v;
if (var == null)
{
return(null);
}
if (var.Count() != window.Count)
{
return(null);
}
//检查平台数据是不是比两端的数据大(正平台)或者小(负平台)
double _flat_value = input_data_list[endIndex];
int _left_endpoint_index = endIndex - window.Count;
if (_left_endpoint_index < 0)
{
return(null);
}
int _right_endpoint_index = endIndex + 1;
if (_right_endpoint_index >= input_data_list.Count)
{
return(null);
}
double _left_endpoint_value = input_data_list[_left_endpoint_index];
double _right_endpoint_value = input_data_list[_right_endpoint_index];
if (((_left_endpoint_value > _flat_value) && (_right_endpoint_value > _flat_value)) ||
((_left_endpoint_value < _flat_value) && (_right_endpoint_value < _flat_value)))
{
FlatInfo midflat = new FlatInfo();
midflat.StartIndex = endIndex - window.Count + 1;
midflat.StopIndex = endIndex;
midflat.FlatWidth = window.Count;
return(midflat);
}
else
{
return(null);
}
#region OLD_CODE
//int index = endIndex - window.Count;
//if (index < 0) return null;
//if (bPositiveFlat)
//{
// if (input_data_list[index] >= input_data_list[endIndex]) return null;
//}
//else
//{
// if (input_data_list[index] <= input_data_list[endIndex]) return null;
//}
//index = endIndex + 1;
//if (index >= input_data_list.Count) return null;
//if (bPositiveFlat)
//{
// if (input_data_list[index] >= input_data_list[endIndex]) return null;
//}
//else
//{
// if (input_data_list[index] <= input_data_list[endIndex]) return null;
//}
//FlatInfo midflat = new FlatInfo();
//midflat.StartIndex = endIndex - window.Count + 1;
//midflat.StopIndex = endIndex;
//midflat.FlatWidth = window.Count;
//return midflat;
#endregion
}