Initializes a geodesic on the ellipsoid connecting the two provided planetodetic points.
    
| Name | Type | Default | Description | 
|---|---|---|---|
| start | Cartographic | optional The initial planetodetic point on the path. | |
| end | Cartographic | optional The final planetodetic point on the path. | |
| ellipsoid | Ellipsoid | Ellipsoid.WGS84 | optional The ellipsoid on which the geodesic lies. | 
Members
readonly ellipsoid : Ellipsoid
    Gets the ellipsoid.
readonly end : Cartographic
    Gets the final planetodetic point on the path.
    Gets the heading at the final point.
readonly start : Cartographic
    Gets the initial planetodetic point on the path.
    Gets the heading at the initial point.
    Gets the surface distance between the start and end point
Methods
interpolateUsingFraction(fraction, result) → Cartographic
    Provides the location of a point at the indicated portion along the geodesic.
    
| Name | Type | Description | 
|---|---|---|
| fraction | Number | The portion of the distance between the initial and final points. | 
| result | Cartographic | optional The object in which to store the result. | 
Returns:
    The location of the point along the geodesic.
    
interpolateUsingSurfaceDistance(distance, result) → Cartographic
    Provides the location of a point at the indicated distance along the geodesic.
    
| Name | Type | Description | 
|---|---|---|
| distance | Number | The distance from the inital point to the point of interest along the geodesic | 
| result | Cartographic | optional The object in which to store the result. | 
Returns:
    The location of the point along the geodesic.
    
Throws:
- 
    DeveloperError : start and end must be set before calling function interpolateUsingSurfaceDistance
    Sets the start and end points of the geodesic
    
| Name | Type | Description | 
|---|---|---|
| start | Cartographic | The initial planetodetic point on the path. | 
| end | Cartographic | The final planetodetic point on the path. | 
