Pix2Sky_BonneEqualArea

class astropy.modeling.projections.Pix2Sky_BonneEqualArea(theta1=0.0, **kwargs)[source]

Bases: astropy.modeling.projections.Pix2SkyProjection, astropy.modeling.projections.PseudoConic

Bonne’s equal area pseudoconic projection - pixel to sky.

Corresponds to the BON projection in FITS WCS.

\[\begin{split}\phi &= \frac{\pi}{180^\circ} A_\phi R_\theta / \cos \theta \\ \theta &= Y_0 - R_\theta\end{split}\]

where:

\[\begin{split}R_\theta &= \mathrm{sign} \theta_1 \sqrt{x^2 + (Y_0 - y)^2} \\ A_\phi &= \arg\left(\frac{Y_0 - y}{R_\theta}, \frac{x}{R_\theta}\right)\end{split}\]
Parameters
theta1float

Bonne conformal latitude, in degrees.

Attributes Summary

param_names

Names of the parameters that describe models of this type.

theta1

Methods Summary

evaluate(x, y, theta1)

Evaluate the model on some input variables.

Attributes Documentation

param_names = ('theta1',)

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.

theta1 = Parameter('theta1', value=0.0)

Methods Documentation

classmethod evaluate(x, y, theta1)[source]

Evaluate the model on some input variables.