Use quaternions instead of 3*3 matrices to represent rotations.

1 files changed, 5 insertions, 5 deletions

diff --git a/org/madore/ephem/Precession.java b/org/madore/ephem/Precession.java
index 8b556d5..af8a1dc 100644
--- a/org/madore/ephem/Precession.java
+++ b/org/madore/ephem/Precession.java
@@ -15,11 +15,11 @@ public final class Precession {
     public static Comput.Polynomial eqorg
 	= new Comput.Polynomial(0.014506, 4612.156534, 1.3915817, -0.00000044, -0.000029956, -0.0000000368);
 
-    public static Frames.RotationMatrix matrix(double t) {
-	Frames.RotationMatrix mat1 = Frames.RotationMatrix.rotx(epsilon0*Comput.arcsecond);
-	Frames.RotationMatrix mat2 = Frames.RotationMatrix.rotz(-psi.v(t)*Comput.arcsecond).apply(mat1);
-	Frames.RotationMatrix mat3 = Frames.RotationMatrix.rotx(-omega.v(t)*Comput.arcsecond).apply(mat2);
-	Frames.RotationMatrix mat4 = Frames.RotationMatrix.rotz(chi.v(t)*Comput.arcsecond).apply(mat3);
+    public static Frames.Rotation matrix(double t) {
+	Frames.Rotation mat1 = Frames.Rotation.rotx(epsilon0*Comput.arcsecond);
+	Frames.Rotation mat2 = Frames.Rotation.rotz(-psi.v(t)*Comput.arcsecond).apply(mat1);
+	Frames.Rotation mat3 = Frames.Rotation.rotx(-omega.v(t)*Comput.arcsecond).apply(mat2);
+	Frames.Rotation mat4 = Frames.Rotation.rotz(chi.v(t)*Comput.arcsecond).apply(mat3);
 	return mat4;
     }