Fix arcsin domain error

scottshambaugh · scottshambaugh · commit e497c77f6b5c · 2024-09-15T21:40:41.000-04:00
diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -4023,9 +4023,10 @@ def as_cardan_angles(self):
         The inverse of `from_cardan_angles()`.
         Note that the angles returned are in radians, not degrees.
         """
-        qw = self.scalar
-        qx, qy, qz = self.vector[..., :]
+        n = np.sqrt(self.norm)
+        qw = self.scalar / n
+        qx, qy, qz = self.vector[..., :] / n
         azim = np.arctan2(2*(-qw*qz+qx*qy), qw*qw+qx*qx-qy*qy-qz*qz)
-        elev = np.arcsin( 2*( qw*qy+qz*qx)/(qw*qw+qx*qx+qy*qy+qz*qz))  # noqa E201
+        elev = np.arcsin(np.clip(2*(qx*qz + qw*qy), -1, 1))
         roll = np.arctan2(2*( qw*qx-qy*qz), qw*qw-qx*qx-qy*qy+qz*qz)   # noqa E201
         return elev, azim, roll
