Pix2Sky_SlantOrthographic¶
-
class
astropy.modeling.projections.
Pix2Sky_SlantOrthographic
(xi=0.0, eta=0.0, **kwargs)[source]¶ 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
- xifloat
Obliqueness parameter, ξ. Default is 0.0.
- etafloat
Obliqueness parameter, η. Default is 0.0.
Attributes Summary
Methods Summary
evaluate
(x, y, xi, eta)Evaluate the model on some input variables.
Attributes Documentation
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eta
= Parameter('eta', value=0.0)¶
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param_names
= ('xi', 'eta')¶
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xi
= Parameter('xi', value=0.0)¶
Methods Documentation