//Two recursive algorithms are used:
//------1st goes through all the latitudes (1st column) - binary search method is utilized
//------2nd establishes an initial step and them goes through the data, if search direction
//is flipped then the step is reduced
public IMultipleValueDataPoint2D FindPointInDataFileRecursive(decimal Latitude, decimal Longitude, int startIndex, int EndIndex)
{
int chunkSize = 1 + (EndIndex - startIndex);
if (chunkSize <= 0)
{
return(null);
}
int currentIndex = startIndex + (chunkSize / 2);
IMultipleValueDataPoint2D FirstPointWithGivenLatitude = readPointValue(currentIndex);
if (FirstPointWithGivenLatitude.Latitude == Latitude)
{
IMultipleValueDataPoint2D foundPoint = FindPointInDataFileByLongitudeRecursive(FirstPointWithGivenLatitude, currentIndex, Latitude, Longitude, CurrentIncrementDirection.Unknown, 100);
return(foundPoint);
}
else //if latitude did not match
{
if (FirstPointWithGivenLatitude.Latitude > Latitude)
{
return(FindPointInDataFileRecursive(Latitude, Longitude, currentIndex + 1, EndIndex));
}
else
{
return(FindPointInDataFileRecursive(Latitude, Longitude, startIndex, currentIndex - 1));
}
}
}
public MapDataElement
(
decimal Latitude, decimal Longitude,
IMultipleValueDataPoint2D LowerLeftPoint,
IMultipleValueDataPoint2D LowerRightPoint,
IMultipleValueDataPoint2D UpperLeftPoint,
IMultipleValueDataPoint2D UpperRightPoint)
{
this.latitude = Latitude;
this.longitude = Longitude;
this.LowerLeftPoint = LowerLeftPoint;
this.LowerRightPoint = LowerRightPoint;
this.UpperLeftPoint = UpperLeftPoint;
this.UpperRightPoint = UpperRightPoint;
}
protected MapDataElement ReadData(decimal Latitude, decimal Longitude, ReadPointValueDelegate ReadPointValue, decimal DataCoordinateStep)
{
this.readPointValue = ReadPointValue;
//find the lower-left cornerpoint of a quad
decimal LatLow = Latitude.FloorWithSignificance(DataCoordinateStep);
decimal LongLow = Longitude.FloorWithSignificance(DataCoordinateStep);
//SeismicGroundMotionDataPoint pointFound = this.FindPointInDataFileRecursive(LatLow, LongLow, DataStartIndex+1, DataEndIndex);
IMultipleValueDataPoint2D foundPoint = this.FindPointInDataFileRecursive(LatLow, LongLow, DataStartIndex + 1, DataEndIndex);
MapDataElement de = new MapDataElement(Latitude, Longitude);
//add neigboring points for interpolation
#region Neigbouring points for interpolation
#region Special cases
//Corner points
if (foundPoint.DataArrayIndex == DataStartIndex + 1 || foundPoint.DataArrayIndex == NumberOfColumns + 1 || foundPoint.DataArrayIndex == DataEndIndex || foundPoint.DataArrayIndex == DataEndIndex - NumberOfColumns + 1)
{
de.LowerLeftPoint = foundPoint;
de.LowerRightPoint = foundPoint.Clone();
de.LowerRightPoint.Longitude = de.LowerRightPoint.Longitude + CoordinateIncrement;
de.UpperLeftPoint = foundPoint.Clone();
de.UpperLeftPoint.Latitude = de.UpperLeftPoint.Latitude + CoordinateIncrement;
de.UpperRightPoint = foundPoint.Clone();
de.UpperRightPoint.Latitude = de.UpperRightPoint.Latitude + CoordinateIncrement;
de.UpperRightPoint.Longitude = de.UpperRightPoint.Longitude + CoordinateIncrement;
return(de);
}
//bottom row- do nothing
//top row
if (foundPoint.DataArrayIndex < (NumberOfColumns + 1))
{
de.LowerLeftPoint = foundPoint;
IMultipleValueDataPoint2D pNextLongitude = readPointValue(foundPoint.DataArrayIndex + 1);
de.LowerRightPoint = pNextLongitude;
IMultipleValueDataPoint2D NextLatitudePoint = foundPoint.Clone();
NextLatitudePoint.Latitude = foundPoint.Latitude + CoordinateIncrement;
de.UpperLeftPoint = NextLatitudePoint;
IMultipleValueDataPoint2D NextLatitudeAndLongitudePoint = pNextLongitude.Clone();
NextLatitudeAndLongitudePoint.Latitude = foundPoint.Latitude + CoordinateIncrement;
NextLatitudeAndLongitudePoint.Longitude = foundPoint.Longitude + CoordinateIncrement;
de.UpperRightPoint = NextLatitudeAndLongitudePoint;
return(de);
}
//first column -do nothing
//last column
if ((foundPoint.DataArrayIndex - DataStartIndex) % (NumberOfColumns) == 0 && foundPoint.DataArrayIndex > 2)
{
de.LowerLeftPoint = foundPoint;
IMultipleValueDataPoint2D pNextLongitude = foundPoint.Clone();
pNextLongitude.Longitude = foundPoint.Longitude + CoordinateIncrement;
de.LowerRightPoint = pNextLongitude;
IMultipleValueDataPoint2D pNextLatitude = readPointValue(foundPoint.DataArrayIndex - NumberOfColumns);
de.UpperLeftPoint = pNextLatitude;
IMultipleValueDataPoint2D NextLatitudeAndLongitudePoint = pNextLatitude.Clone();
NextLatitudeAndLongitudePoint.Latitude = pNextLatitude.Latitude;
NextLatitudeAndLongitudePoint.Longitude = pNextLongitude.Longitude;
de.UpperRightPoint = NextLatitudeAndLongitudePoint;
return(de);
}
#endregion
#region Typical case
de.LowerLeftPoint = foundPoint;
de.LowerRightPoint = readPointValue(foundPoint.DataArrayIndex + 1); //NextLongitudePoint;
de.UpperLeftPoint = readPointValue(foundPoint.DataArrayIndex - NumberOfColumns); //NextLatitudePoint;
de.UpperRightPoint = readPointValue(foundPoint.DataArrayIndex - NumberOfColumns + 1); //NextLatitudeAndLongitudePoint
#endregion
#endregion
//Interpolation is done by MapDataElement
//if (pointFound!=null)
//{
// decimal SS = GetInterpolatedValue(pointFound, Latitude, Longitude, GroundMotionParameterType.SS);
// decimal S1 = GetInterpolatedValue(pointFound, Latitude, Longitude, GroundMotionParameterType.S1);
// return new SeismicGroundMotionDataPoint(Latitude, Longitude, SS, S1);
//}
//return new SeismicGroundMotionDataPoint();
return(de);
}
private IMultipleValueDataPoint2D FindPointInDataFileByLongitudeRecursive(IMultipleValueDataPoint2D CurrentPoint, int currentIndex, decimal Latitude, decimal Longitude,
CurrentIncrementDirection incrementDirection, int Step)
{
decimal thisLongitude = CurrentPoint.Longitude;
if (thisLongitude == Longitude)
{
return(CurrentPoint);
}
else // if did not hot the target
{
#region Current longitude less than target
if (thisLongitude < Longitude)
{
if (incrementDirection == CurrentIncrementDirection.Increase)
{
Step = (int)Step / 2;
}
incrementDirection = CurrentIncrementDirection.Decrease;
currentIndex = (currentIndex + Step) <= DataEndIndex ? currentIndex + Step : DataEndIndex;
CurrentPoint = readPointValue(currentIndex);
//case when this is a boundary condition
if (currentIndex >= DataEndIndex - NumberOfColumns) // if this is the last row in the table
{
int count1 = 0;
while (CurrentPoint.Longitude != Longitude) //increment by one
{
currentIndex = currentIndex + 1;
CurrentPoint = readPointValue(currentIndex);
count1++;
if (count1 > NumberOfColumns)
{
throw new Exception("Data point not found in table.");
}
}
return(CurrentPoint);
}
if (CurrentPoint.Latitude != Latitude) //this means we overshot
{
//step one by one to go find value
while (CurrentPoint.Latitude != Latitude && CurrentPoint.Longitude != Longitude)
{
currentIndex = currentIndex - 1;
CurrentPoint = readPointValue(currentIndex);
}
return(CurrentPoint);
}
else
{
//continue recursive iteration
return(FindPointInDataFileByLongitudeRecursive(CurrentPoint, currentIndex,
Latitude, Longitude, incrementDirection, Step));
}
}
#endregion
#region Current longitude greater than target
else //(thisLongitude>Longitude)
{
if (incrementDirection == CurrentIncrementDirection.Decrease)
{
Step = (int)Step / 2;
}
incrementDirection = CurrentIncrementDirection.Increase;
currentIndex = Step <= currentIndex ? currentIndex - Step : currentIndex - 1;
CurrentPoint = readPointValue(currentIndex);
//case when this is a boundary condition
if (currentIndex < NumberOfColumns) // if this is the first row in the table
{
int count2 = 0;
while (CurrentPoint.Longitude != Longitude) //increment by one
{
currentIndex = currentIndex - 1;
CurrentPoint = readPointValue(currentIndex);
count2++;
if (count2 > NumberOfColumns)
{
throw new Exception("Data point not found in table.");
}
}
return(CurrentPoint);
}
if (CurrentPoint.Latitude != Latitude) //this means we overshot
{
//step one by one to go find value
while (CurrentPoint.Latitude != Latitude && CurrentPoint.Longitude != Longitude)
{
currentIndex = currentIndex + 1;
CurrentPoint = readPointValue(currentIndex);
}
return(CurrentPoint);
}
else
{
//continue recursive iteration
return(FindPointInDataFileByLongitudeRecursive(CurrentPoint, currentIndex,
Latitude, Longitude, incrementDirection, Step));
}
}
#endregion
}
}
