Sky2Pix_ZenithalPerspective

class astropy.modeling.projections.Sky2Pix_ZenithalPerspective(mu=0.0, gamma=0.0, **kwargs)

Bases: astropy.modeling.projections.Sky2PixProjection, astropy.modeling.projections.Zenithal

Zenithal perspective projection - sky to pixel.

Corresponds to the AZP projection in FITS WCS.

\[\begin{split}x &= R \sin \phi \\ y &= -R \sec \gamma \cos \theta\end{split}\]

where:

\[R = \frac{180^{\circ}}{\pi} \frac{(\mu + 1) \cos \theta}{(\mu + \sin \theta) + \cos \theta \cos \phi \tan \gamma}\]

Parameters:

mu : float

Distance from point of projection to center of sphere in spherical radii, μ. Default is 0.

gamma : float

Look angle γ in degrees. Default is 0°.

Attributes Summary

gamma
mu
param_names

Methods Summary

evaluate(phi, theta, mu, gamma)

Evaluate the model on some input variables.

Attributes Documentation

gamma = Parameter('gamma', value=0.0)

mu = Parameter('mu', value=0.0)

param_names = ('mu', 'gamma')

Methods Documentation

classmethod evaluate(phi, theta, mu, gamma)

Evaluate the model on some input variables.