Crs.FromArea Method
Returns a new Coordinate Reference System, suitable for a given rectangular area.
FromArea(Point longLatSW, Point longLatNE, GeodeticDatum geodeticDatum)
Returns a new Coordinate Reference System, suitable for a given rectangular area.Syntax
public static Crs FromArea (
Point longLatSW,
Point longLatNE,
GeodeticDatum geodeticDatum
)Parameters
The southwest corner of the area, expressed in LongLat.
The northeast corner of the area, expressed in LongLat.
Return Value
A Crs suitable for the given area.
Remarks
The new Coordinate Reference System will have a conformal projection with coordinates in meters, suitable for the given rectangular area. (The given rectangle may cross meridian 180°; then longLatSW.X will be numerically greater than longLatNE.X). Such a projection lets your application calculate in plane geometry (perhaps by using the Geometry classes). If the rectangle is sufficiently small, a conformal projection is almost perfect in other respects as well: its scale will be almost constant, great circle routes will appear almost straight, areas of polygons will be almost correct, etc. For larger rectangles, the accuracy decreases, but it is tricky to say when it becomes too bad. It depends on your accuracy requirements and the nature of the plane geometry calculations. For some purposes, a non-conformal projection would be better for large rectangles - for example, you can use a azimuthal equal-area projection if you want to compute areas of large polygons.
Platforms
Windows, Linux, Android