public decimal GetValue(object ValueParameter, bool UseInterpolation = true,
decimal InterpolationAdjustment = 1.0m, decimal AdjustmentProximityLength = 1.0m)
{
decimal ValLowerLeftPoint = LowerLeftPoint.GetValue(ValueParameter);
decimal ValLowerRightPoint = LowerRightPoint.GetValue(ValueParameter);
decimal ValUpperLeftPoint = UpperLeftPoint.GetValue(ValueParameter);
decimal ValUpperRightPoint = UpperRightPoint.GetValue(ValueParameter);
decimal retVal;
if (UseInterpolation == true)
{
Quad Quad = new Quad()
{
LowerLeftPoint = new DataPoint2D(LowerLeftPoint.Longitude, LowerLeftPoint.Latitude, ValLowerLeftPoint),
LowerRightPoint = new DataPoint2D(LowerRightPoint.Longitude, LowerRightPoint.Latitude, ValLowerRightPoint),
UpperLeftPoint = new DataPoint2D(UpperLeftPoint.Longitude, UpperLeftPoint.Latitude, ValUpperLeftPoint),
UpperRightPoint = new DataPoint2D(UpperRightPoint.Longitude, UpperRightPoint.Latitude, ValUpperRightPoint)
};
retVal = Quad.GetInterpolatedValue(Longitude, Latitude, InterpolationAdjustment, AdjustmentProximityLength);
}
else
{
List <decimal> ValList = new List <decimal> {
ValLowerLeftPoint, ValLowerRightPoint, ValUpperLeftPoint, ValUpperRightPoint
};
retVal = ValList.Max();
}
return(retVal);
}
public decimal GetInterpolatedValue(decimal XAbsolute, decimal YAbsolute, decimal InterpolationAdjustment = 1.0m,
decimal AdjustmentProximityLength = 1.0m)
//if the value is interpolated an adjustment is introduced to account for the
//difference between USGS more precise calculation and this procedure
{
decimal x = XAbsolute;
decimal y = YAbsolute;
decimal x1 = LowerLeftPoint.X;
decimal x2 = UpperRightPoint.X;
decimal y1 = LowerLeftPoint.Y;
decimal y2 = UpperRightPoint.Y;
decimal R1 = ((x2 - x) / (x2 - x1)) * LowerLeftPoint.Value + ((x - x1) / (x2 - x1)) * LowerRightPoint.Value;
decimal R2 = ((x2 - x) / (x2 - x1)) * UpperLeftPoint.Value + ((x - x1) / (x2 - x1)) * UpperRightPoint.Value;
decimal P = ((y2 - y) / (y2 - y1)) * R1 + ((y - y1) / (y2 - y1)) * R2;
DataPoint2D readingPoint = new DataPoint2D(XAbsolute, YAbsolute, 0);
//it is assumed that the middle 2/3 need adjustment closer to the gridded points no adjustment is made
decimal t = Math.Min(Math.Abs(LowerRightPoint.X - LowerLeftPoint.X), Math.Abs(LowerRightPoint.Y - UpperLeftPoint.Y)) / AdjustmentProximityLength;
if (!LowerLeftPoint.IsNear(readingPoint, t) && !LowerRightPoint.IsNear(readingPoint, t) &&
!UpperLeftPoint.IsNear(readingPoint, t) && !UpperRightPoint.IsNear(readingPoint, t))
{
List <decimal> values = new List <decimal>()
{
LowerLeftPoint.Value,
LowerRightPoint.Value,
UpperLeftPoint.Value,
UpperRightPoint.Value
};
decimal MaxVal = values.Max();
decimal P_adjusted = P * InterpolationAdjustment;
decimal P_final = Math.Min(MaxVal, P_adjusted);
return(P_final);
}
else
{
return(P);
}
}