public static double CalcAcc(double latitudeBefore, double longitudeBefore,
double latitudeThis, double longitudeThis,
double latitudeAfter, double longitudeAfter, double samplingTime)
{
//中間差分法による導出
return (DistanceCalculator.CalcDistance(latitudeThis, longitudeThis, latitudeAfter, longitudeAfter)
- DistanceCalculator.CalcDistance(latitudeBefore, longitudeBefore, latitudeThis, longitudeBefore)) / Math.Pow(samplingTime, 2);
}
/** km/h の速度を返す **/
public static double CalcSpeed(double latitudeBefore, double longitudeBefore, DateTime timeBefore, double latitudeAfter, double longitudeAfter, DateTime timeAfter,
double latitudeFocused, double longitudeFocused)
{
//中間差分法を用いた導出
//return DistanceCalculator.CalcDistance(latitudeBefore, longitudeBefore, latitudeAfter, longitudeAfter) / 2 / samplingSeconds * 3.6;
return((DistanceCalculator.CalcDistance(latitudeBefore, longitudeBefore, latitudeFocused, longitudeFocused) +
DistanceCalculator.CalcDistance(latitudeFocused, longitudeFocused, latitudeAfter, longitudeAfter)) /
(timeAfter - timeBefore).TotalSeconds * 3.6);
}
private string SelectLink(double latitude, double longitude, double heading, DataRow[] selectedRows)
{
string matchedLink = "";
double minDistance = double.PositiveInfinity;
double linkDistance = double.PositiveInfinity;
//車のHEADINGを計算
double carHeading;
if (heading > 180)
{
carHeading = heading - 180;
}
else
{
carHeading = heading;
}
//自動車の向きとリンクの向きのなす角
double minAngle = double.PositiveInfinity;
Boolean flag = true;
foreach (DataRow row in selectedRows)
{
double pointY; //リンク上のGPSの点との最近点の緯度
double pointX; //リンク上のGPSの点との最近点の経度
//リンクとGPS上の点との距離とリンク上の最近点を計算
CalculateMinimumDistancePointOfLink(latitude, longitude, row, out pointY, out pointX);
//リンクとの最短距離
double distance = DistanceCalculator.CalcDistance(latitude, longitude, pointY, pointX);
if (row.Field <double?>("heading") != null)
{
double linkHeading = row.Field <double>("heading");
//リンクとHEADINGの角度を算出
double angle = Math.Abs(carHeading - linkHeading);
if (angle > 90)
{
angle = 180 - angle;
}
if (linkDistance >= distance)
{
//リンクとの距離が10m以内でかつなす角が小さいものをマッチング
if (distance < 10 && (minAngle - angle > 3 ||
(Math.Abs(minAngle - angle) <= 3 && linkDistance > distance)))
{
linkDistance = distance;
minAngle = angle;
matchedLink = row.Field <string>("link_id").Trim();
flag = false;
}
//10m以内のリンクがないときは距離が短いものをマッチング
else if (minDistance >= distance && flag)
{
minDistance = distance;
matchedLink = row.Field <string>("link_id").Trim();
}
}
}
else
{
//Headingが計算できないときは距離が短いものをマッチング
if (minDistance >= distance && flag)
{
minDistance = distance;
matchedLink = row.Field <string>("link_id").Trim();
}
}
}
return(matchedLink);
}