private void ChordStats()
{
ChordLength = LatLongCalc.Distance(EndLat, EndLon, StartLat, StartLon);
ChordArcAngle = LatLongCalc.Deg2Rad(Math.Abs(StartBrg = EndBrg));
ChordArcLength = ChordArcAngle * ArcRadius;
ChordRadius = ChordArcLength / 2;
ChordLengthTextBox.Text = ChordLength.ToString("F3");
ChordRadiusTextBox.Text = ChordRadius.ToString("F3");
ChordArcLengthTextBox.Text = ChordArcLength.ToString("F3");
}
public static PointF RotatePoint(PointF pointToRotate, PointF centerPoint, double angleInDegrees)
{
// Given a center point and point to rotate (aka a line), rotate the line X degrees
double radians = LatLongCalc.Deg2Rad(angleInDegrees);
double sin = Math.Sin(radians);
double cos = Math.Cos(radians);
// Translate point back to origin
pointToRotate.X -= centerPoint.X;
pointToRotate.Y -= centerPoint.Y;
// Rotate point
double xnew = pointToRotate.X * cos - pointToRotate.Y * sin;
double ynew = pointToRotate.X * sin + pointToRotate.Y * cos;
// Translate point back
PointF newPoint = new PointF((float)xnew + centerPoint.X, (float)ynew + centerPoint.Y);
return(newPoint);
}
public static double NMperLongDegree()
{
// Assumes all Lat/Longs are in Decimal degrees
double DegPerNMequator = 69.172;
double radCenterLat;
// Use the user's desired center if possible
if (InfoSection.CenterLatitude_Dec == 0)
{
radCenterLat =
LatLongCalc.Deg2Rad((FilterBy.NorthLimit + FilterBy.SouthLimit) / 2);
}
else
{
radCenterLat = LatLongCalc.Deg2Rad(InfoSection.CenterLatitude_Dec);
}
double result = Math.Cos(radCenterLat) * DegPerNMequator;
return(result);
}
