Pix2Sky_ConicEquidistant

class astropy.modeling.projections.Pix2Sky_ConicEquidistant(*args, meta=None, name=None, **kwargs)[source]

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

Conic equidistant projection - pixel to sky.

Corresponds to the COD projection in FITS WCS.

See Conic for a description of the entire equation.

The projection formulae are:

\[\begin{split}C &= \frac{180^\circ}{\pi} \frac{\sin\theta_a\sin\eta}{\eta} \\ R_\theta &= \theta_a - \theta + \eta\cot\eta\cot\theta_a \\ Y_0 = \eta\cot\eta\cot\theta_a\end{split}\]
Parameters:
sigma : float

\((\theta_1 + \theta_2) / 2\), where \(\theta_1\) and \(\theta_2\) are the latitudes of the standard parallels, in degrees. Default is 90.

delta : float

\((\theta_1 - \theta_2) / 2\), where \(\theta_1\) and \(\theta_2\) are the latitudes of the standard parallels, in degrees. Default is 0.

Methods Summary

evaluate(x, y, sigma, delta) Evaluate the model on some input variables.

Methods Documentation

classmethod evaluate(x, y, sigma, delta)[source]

Evaluate the model on some input variables.