Pix2Sky_ZenithalPerspective¶
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class
astropy.modeling.projections.
Pix2Sky_ZenithalPerspective
(mu=0.0, gamma=0.0, **kwargs)[source]¶ Bases:
astropy.modeling.projections.Pix2SkyProjection
,astropy.modeling.projections.Zenithal
Zenithal perspective projection - pixel to sky.
Corresponds to the
AZP
projection in FITS WCS.\[\begin{split}\phi &= \arg(-y \cos \gamma, x) \\ \theta &= \left\{\genfrac{}{}{0pt}{}{\psi - \omega}{\psi + \omega + 180^{\circ}}\right.\end{split}\]where:
\[\begin{split}\psi &= \arg(\rho, 1) \\ \omega &= \sin^{-1}\left(\frac{\rho \mu}{\sqrt{\rho^2 + 1}}\right) \\ \rho &= \frac{R}{\frac{180^{\circ}}{\pi}(\mu + 1) + y \sin \gamma} \\ R &= \sqrt{x^2 + y^2 \cos^2 \gamma}\end{split}\]- Parameters
- mufloat
Distance from point of projection to center of sphere in spherical radii, μ. Default is 0.
- gammafloat
Look angle γ in degrees. Default is 0°.
Attributes Summary
Methods Summary
evaluate
(x, y, mu, gamma)Evaluate the model on some input variables.
Attributes Documentation
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gamma
= Parameter('gamma', value=0.0)¶
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mu
= Parameter('mu', value=0.0)¶
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param_names
= ('mu', 'gamma')¶
Methods Documentation