abstract class WholeSkyProjection extends Object implements Projection
For whole-sky projections, it's convenient to transform to numbers that can be plugged directly into typical formulas for map projections, that use latitude and longitude (positive east of the prime meridian).
In essence, this effects a 90 degree rotation, changing from a pole-on view using (r,theta,phi) and having the z-axis into the screen, to a pole-up view, with latitude up-down, and longitude left-right.
Constructor and Description |
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WholeSkyProjection() |
Modifier and Type | Method and Description |
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Coords |
project(double aThetaprime,
double aPhi,
double aScale,
Coords aCenter)
Return the coordinates of the star, ready for rendering on an image context.
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(package private) abstract Coords |
projectWithLatLong(double aLatitude,
double aLongitude,
double aScale,
Coords aCenter)
Use a projection formula expressed in latitude and longitude.
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WholeSkyProjection()
public final Coords project(double aThetaprime, double aPhi, double aScale, Coords aCenter)
Projection
The two arguments correspond to two angles on the celestial sphere. These two angles can take a different meaning according to context. For example, in the simple case of stereographic projection centered on the North Celestial Pole, the two arguments correspond to the (aberrated) zenith angle from the Pole and the right ascension, respectively. For the full-sky projections, the two arguments correspond more to latitude and longitude (declination and right ascension), respectively.
project
in interface Projection
abstract Coords projectWithLatLong(double aLatitude, double aLongitude, double aScale, Coords aCenter)
Starfield - Copyright Hirondelle Systems. Published March 1, 2014