public static List <BreakPointInfo> AnalyzeOneTrajectory(GPSTrajectory traj)
{
if (traj.GPSCount <= 3)
{
throw new Exception("GPS轨迹数据点太少");
}
List <BreakPointInfo> breakinfo = new List <BreakPointInfo>();
TransportationMode last = InWhichMode(traj[1].Velocity);
int duration = 1;
for (int i = 2; i < traj.GPSCount; i++)
{
TransportationMode mode = InWhichMode(traj[i].Velocity);
if (mode != last)
{
//检测到移动模式变化
BreakPointInfo bpinfo = new BreakPointInfo(i - 1, last, duration);
breakinfo.Add(bpinfo);
duration = 1;
}
else
{
duration++;
}
last = mode;
}
//处理最后一个点
if (duration != 1)
{
breakinfo.Add(new BreakPointInfo(traj.GPSCount - 1, last, duration));
}
return(breakinfo);
}
public static UsersTrajectories ReadAll(string filename)
{
UsersTrajectories myUserTrajectories = new UsersTrajectories();
using (StreamReader sr = new StreamReader(filename))
{
while (!sr.EndOfStream)
{
GPSTrajectory gt = ReadLine(sr.ReadLine());
myUserTrajectories.InsertTrajectories(gt);
}
return(myUserTrajectories);
}
}
public static string SingleTrajectoryToBaiduMapJson(GPSTrajectory path)
{
StringBuilder data = new StringBuilder();
for (int i = 0; i < path.GPSCount; i++)
{
data.AppendFormat("{0},{1}", path[i].X, path[i].Y);
if (i != path.GPSCount - 1)
{
data.Append(",");
}
}
return(data.ToString());
}
public static GPSTrajectory ReadLine(string line)
{
int split = line.IndexOf('\t');
int num = int.Parse(line.Substring(0, split));
GPSTrajectory gt = new GPSTrajectory(num);
string[] data = line.Substring(split + 1).Split(new char[] { ',', '|' });
for (int i = 0; i < data.Length; i++)
{
int time = int.Parse(data[i++]);
float lo = float.Parse(data[i++]);
float la = float.Parse(data[i]);
gt.AddPoint(lo, la, time);
}
return(gt);
}
private GPSTrajectory Simplify()
{
_usePt = new bool[GPSPts.GPSCount];
for (int i = 0; i < GPSPts.GPSCount; i++)
{
_usePt[i] = true;
}
SimplifySection(0, GPSPts.GPSCount - 1);
GPSTrajectory simplifiedLine = new GPSTrajectory(GPSPts.UserID);
for (int i = 0; i < GPSPts.GPSCount; i++)
{
if (_usePt[i])
{
simplifiedLine.AddPoint(GPSPts[i]);
}
}
return(simplifiedLine);
}
public string GetOneTrajectory(int userID, int index)
{
GPSTrajectory gt = myUserTrajectories.GetTrajectoriesByUserID(userID)[index];
string result = gt.ToJSON();
//添加速度
StringBuilder sb = new StringBuilder();
sb.Append("\"Velocity\":[0,");
for (int i = 1; i < gt.GPSCount; i++)
{
sb.Append(gt[i].Velocity * 3.6);
if (i != gt.GPSCount - 1)
{
sb.Append(',');
}
}
sb.Append(']');
return(JSONConverter.AddElementsToJSON(result, sb.ToString()));
}
public static string SingleTrajectoryToJson(GPSTrajectory item)
{
StringBuilder sb = new StringBuilder();
sb.Append("[");
sb.Append("{'geo':[");
for (int i = 0; i < item.GPSCount; i++)
{
sb.AppendFormat("[{0},{1},{2}]", item[i].X, item[i].Y, item[i].TimeStamp);
if (i != item.GPSCount - 1)
{
sb.Append(",");
}
}
sb.Append("],'count':1},");
sb.Remove(sb.Length - 1, 1);//移除最后一个逗号
sb.Append("]");
return(sb.ToString());
}
public GPSTrajectory Excute(GPSTrajectory source, double maxdistance)
{
_distanceTolerance = maxdistance;
GPSPts = source;
return(Simplify());
}
/// <summary>
/// 构造函数
/// </summary>
/// <param name="traj">GPS轨迹</param>
/// <param name="maxdistance">最大阈值</param>
public GPSDouglasSimplification(GPSTrajectory traj, double maxdistance)
{
GPSPts = traj;
_distanceTolerance = maxdistance;
}
