virtual double MgCoordinateSystem::GetAzimuth	(	double	x1,
		double	y1,
		double	x2,
		double	y2
	)		[pure virtual]

Gets the angle with respect to North of a vector formed by two coordinate.

Parameters:

x1	The first X coordinate
y1	The first Y coordinate
x2	The second X coordinate
y2	The second Y coordinate

Returns:

The azimuth (Angle with respect to the North) of the vector formed by (x1, y1) and (x2, y2)

Remarks:

This method is specific to a geographic coordinate system. The angle is positive moving clockwise from North and negative moving counterclockwise from North. If the first coordinate is above and to the left of the second, or below and to the left, the movement is clockwise. If the first coordinate is above and to the right, or below and to the right, the movement is counterclockwise