DMA Release 0.8 Copyright ©1995 by Genesis Project, Ltd. All Rights Reserved.
MiscIrelandUTMCoord |
Inherits From: | MiscUTMCoord : MiscCoord : Object | |
Declared In: | misckit/miscgiskit/MiscIrelandUTMCoord.h |
Class Description |
A MiscIrelandUTMCoord object contains points in the Irish Universal Transverse Mercator Projection described in
the Irish Ordinance Survey document, "Tables for the Transverse Mercator Projection of Ireland", 1953, reprinted
1971. The addendum with values for the currently used modified airy sphere has been applied. All distances are in
meters.
MiscIrelandUTMCoords use an MiscIrelandCoordConverter object as the default converter for convert:to: operations (See MiscCoord). This related class is invisible to the user and handles conversion between the basic types discussed above. It is used because the Irish Grid uses slightly different equations to convert between UTM and world coordinates than the UK and UTM Zone equations. The first time a MiscIrelandUTMCoord is created, a single instance of a MiscUTMConstants object is created with values particular to this grid. |
World coordinate of True Origin: | Latitude 53.5 N, Longitude 8.0 W | |
True origin offset from grid origin: | 200000.0 meters East , 250000.0 meters North | |
Airy sphere: | a=6377563.396 meters, b=6356256.910 meters | |
Scaling at Central Meridian: | 1.000035 |
This invisible constants object is shared by all future instances of MiscIrelandUTMCoord that are created and is protected against deletion. |
Method Types |
Initialization | - initDescription: - awake |
Instance Methods |
awake |
- awake |
Connect to the private local constants object to the unarchived object and free the unarchived constants. You should
never invoke this method directly. Returns self.
initDescription: |
- initDescription:(char*)textString |
Designated initializer for the MiscIrelandUTMCoord class. textString is copied and may be used in describing the set of points. The new object will initially have space for one point. The default conversion contractor for conversion between coordinate systems is set to be the instance of MiscIrelandCoordConverter. |