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
mufloat

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

lamfloat

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)

Evaluate the model on some input variables.

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]

Evaluate the model on some input variables.