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# Pix2Sky_ConicEqualArea

class astropy.modeling.projections.Pix2Sky_ConicEqualArea(*args, **kwargs)

  Bases: `Pix2SkyProjection`, `Conic`

  Alber’s conic equal area projection - pixel to sky.

  Corresponds to the `COE` projection in FITS WCS.

  See `Conic` for a description of the entire equation.

  The projection formulae are:

  \[\begin{split}C &= \gamma / 2 \\ R_\theta &= \frac{180^\circ}{\pi} \frac{2}{\gamma} \sqrt{1 + \sin \theta_1 \sin \theta_2 - \gamma \sin \theta} \\ Y_0 &= \frac{180^\circ}{\pi} \frac{2}{\gamma} \sqrt{1 + \sin \theta_1 \sin \theta_2 - \gamma \sin((\theta_1 + \theta_2)/2)}\end{split}\]

  where:

  \[\gamma = \sin \theta_1 + \sin \theta_2\]
  Parameters:
    sigma `python: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 `python:float`

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