FallbackDatumShift Class
A datum shift with one or more fallbacks.
NuGet/Assembly: Carmenta.Engine.5.16.2.nupkg (in the CECore assembly)
Syntax
public class FallbackDatumShift : DatumShiftRemarks
A FallbackDatumShift contains a preferred DatumShift, but also one or more fallbacks. The possible datum shifts are stored in the list of Alternatives, and will be tried in order: if one alternative fails for a point, then the next one is tried.
Currently, the only kind of datum shift that can fail is the GridFileDatumShift: if used by itself, such a datum shift will throw an exception outside its coverage, and this may be the best behavior. But sometime you do want a fallback.
One reason for fallbacks can be to enforce a desired priority order for grid shift files, see GridFileDatumShift for an explanation. Another reason can be that you want a fail-safe application, so if you are outside the coverage of the grid shift files, you resort to a HelmertDatumShift and accept that you may get a small discontinuity at the boundary.
Inheritance Hierarchy
System.Object (not available in C#)
EngineObject
ResourceObject
DatumShift
FallbackDatumShift
Platforms
Windows, Linux, Android
FallbackDatumShift Members
The FallbackDatumShift type has the following members.
Constructors
| Name | Description |
|---|---|
| FallbackDatumShift | Initializes a new instance of the FallbackDatumShift class from a list of alternative datum shifts. |
Properties
| Name | Description |
|---|---|
| Alternatives | Gets a read-only collection with the alternative DatumShift instances. |
| Authority | Gets the name of an authority, which is often "epsg". Inherited from DatumShift |
| AuthorityCode | Gets the unique code for the datum shift instance, according to the Authority, for example "15978". Inherited from DatumShift |
| Info | Gets documentation like accuracy and area of use. Inherited from DatumShift |
| IsDisposed | Gets a value that tells whether the current FallbackDatumShift has been disposed. Inherited from EngineObject |
| Name | Gets or sets the name of the FallbackDatumShift. Inherited from ResourceObject |
| NativeHandle | Gets the native Carmenta Engine kernel object the current FallbackDatumShift represents. Inherited from EngineObject |
| IUserProperties.UserProperties | Gets the AttributeSet that contains the user properties. Inherited from IUserProperties |
Methods
| Name | Description |
|---|---|
| Clone | Creates a copy of an object. Inherited from EngineObject |
| Dispose | Releases the reference to the native Carmenta Engine kernel instance the EngineObject represents. Inherited from EngineObject |
| Equals | Determines whether this instance is equal to another. Inherited from EngineObject |
 FromInfo | Constructs a datum shift from a DatumShiftInfo. Inherited from DatumShift |