Sky2Pix_CylindricalPerspective

class astropy.modeling.projections.Sky2Pix_CylindricalPerspective(mu=1.0, lam=1.0, **kwargs)[source]

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

Cylindrical Perspective - sky to pixel.

Corresponds to the CYP projection in FITS WCS.

\[\begin{split}x &= \lambda \phi \\ y &= \frac{180^{\circ}}{\pi}\left(\frac{\mu + \lambda}{\mu + \cos \theta}\right)\sin \theta\end{split}\]
Parameters
mupython:float

Distance from center of sphere in the direction opposite the projected surface, in spherical radii, μ. Default is 0.

lampython:float

Radius of the cylinder in spherical radii, λ. Default is 0.

Attributes Summary

lam

mu

param_names

Names of the parameters that describe models of this type.

Methods Summary

evaluate(phi, theta, mu, lam)

Attributes Documentation

lam = Parameter('lam', value=1.0)
mu = Parameter('mu', value=1.0)
param_names = ('mu', 'lam')

Names of the parameters that describe models of this type.

The parameters in this tuple are in the same order they should be passed in when initializing a model of a specific type. Some types of models, such as polynomial models, have a different number of parameters depending on some other property of the model, such as the degree.

When defining a custom model class the value of this attribute is automatically set by the Parameter attributes defined in the class body.

Methods Documentation

classmethod evaluate(phi, theta, mu, lam)[source]