Pix2Sky_SlantOrthographic¶
-
class
astropy.modeling.projections.
Pix2Sky_SlantOrthographic
(xi=0.0, eta=0.0, **kwargs)[source] [edit on github]¶ Bases:
astropy.modeling.projections.Pix2SkyProjection
,astropy.modeling.projections.Zenithal
Slant orthographic projection - pixel to sky.
Corresponds to the
SIN
projection in FITS WCS.See
Zenithal
for a definition of the full transformation.The following transformation applies when \(\xi\) and \(\eta\) are both zero.
\[\theta = \cos^{-1}\left(\frac{\pi}{180^{\circ}}R_\theta\right)\]The parameters \(\xi\) and \(\eta\) are defined from the reference point \((\phi_c, \theta_c)\) as:
\[\begin{split}\xi &= \cot \theta_c \sin \phi_c \\ \eta &= - \cot \theta_c \cos \phi_c\end{split}\]Parameters: - xi : float
Obliqueness parameter, ξ. Default is 0.0.
- eta : float
Obliqueness parameter, η. Default is 0.0.
Attributes Summary
eta
param_names
xi
Methods Summary
evaluate
(x, y, xi, eta)Evaluate the model on some input variables. Attributes Documentation
-
eta
¶
-
param_names
= ('xi', 'eta')¶
-
xi
¶
Methods Documentation
-
classmethod
evaluate
(x, y, xi, eta)[source] [edit on github]¶ Evaluate the model on some input variables.