# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""
This module defines tools to convert `regions.Region` objects to
Aperture objects.
"""
import astropy.units as u
from photutils.aperture.circle import (CircularAnnulus, CircularAperture,
SkyCircularAnnulus, SkyCircularAperture)
from photutils.aperture.ellipse import (EllipticalAnnulus, EllipticalAperture,
SkyEllipticalAnnulus,
SkyEllipticalAperture)
from photutils.aperture.rectangle import (RectangularAnnulus,
RectangularAperture,
SkyRectangularAnnulus,
SkyRectangularAperture)
__all__ = ['region_to_aperture']
__doctest_requires__ = {'region_to_aperture': ['regions']}
[docs]
def region_to_aperture(region):
"""
Convert a given `regions.Region` object to an
`~photutils.aperture.Aperture` object.
Parameters
----------
region : `regions.Region`
A supported `regions.Region` object.
Returns
-------
aperture : `~photutils.aperture.Aperture`
An equivalent ``photutils`` aperture.
Raises
------
`TypeError`
The given `regions.Region` object is not supported.
Notes
-----
.. |rarr| unicode:: U+0279E .. RIGHTWARDS ARROW
The following `regions.Region` objects are supported, shown with
their equivalent `~photutils.aperture.Aperture` object:
* `~regions.CirclePixelRegion` |rarr|
`~photutils.aperture.CircularAperture`
* `~regions.CircleSkyRegion` |rarr|
`~photutils.aperture.SkyCircularAperture`
* `~regions.EllipsePixelRegion` |rarr|
`~photutils.aperture.EllipticalAperture`
* `~regions.EllipseSkyRegion` |rarr|
`~photutils.aperture.SkyEllipticalAperture`
* `~regions.RectanglePixelRegion` |rarr|
`~photutils.aperture.RectangularAperture`
* `~regions.RectangleSkyRegion` |rarr|
`~photutils.aperture.SkyRectangularAperture`
* `~regions.CircleAnnulusPixelRegion` |rarr|
`~photutils.aperture.CircularAnnulus`
* `~regions.CircleAnnulusSkyRegion` |rarr|
`~photutils.aperture.SkyCircularAnnulus`
* `~regions.EllipseAnnulusPixelRegion` |rarr|
`~photutils.aperture.EllipticalAnnulus`
* `~regions.EllipseAnnulusSkyRegion` |rarr|
`~photutils.aperture.SkyEllipticalAnnulus`
* `~regions.RectangleAnnulusPixelRegion` |rarr|
`~photutils.aperture.RectangularAnnulus`
* `~regions.RectangleAnnulusSkyRegion` |rarr|
`~photutils.aperture.SkyRectangularAnnulus`
Examples
--------
>>> from regions import CirclePixelRegion, PixCoord
>>> from photutils.aperture import region_to_aperture
>>> region = CirclePixelRegion(center=PixCoord(x=10, y=20), radius=5)
>>> aperture = region_to_aperture(region)
>>> aperture
<CircularAperture([10., 20.], r=5.0)>
"""
from regions import (CircleAnnulusPixelRegion, CircleAnnulusSkyRegion,
CirclePixelRegion, CircleSkyRegion,
EllipseAnnulusPixelRegion, EllipseAnnulusSkyRegion,
EllipsePixelRegion, EllipseSkyRegion,
RectangleAnnulusPixelRegion,
RectangleAnnulusSkyRegion, RectanglePixelRegion,
RectangleSkyRegion)
if isinstance(region, CirclePixelRegion):
aperture = CircularAperture(region.center.xy, region.radius)
elif isinstance(region, CircleSkyRegion):
aperture = SkyCircularAperture(region.center, region.radius)
elif isinstance(region, EllipsePixelRegion):
aperture = EllipticalAperture(
region.center.xy, region.width * 0.5, region.height * 0.5,
theta=region.angle.to_value(u.radian))
elif isinstance(region, EllipseSkyRegion):
aperture = SkyEllipticalAperture(
region.center, region.width * 0.5, region.height * 0.5,
theta=(region.angle - (90 * u.deg)))
elif isinstance(region, RectanglePixelRegion):
aperture = RectangularAperture(
region.center.xy, region.width, region.height,
theta=region.angle.to_value(u.radian))
elif isinstance(region, RectangleSkyRegion):
aperture = SkyRectangularAperture(
region.center, region.width, region.height,
theta=(region.angle - (90 * u.deg)))
elif isinstance(region, CircleAnnulusPixelRegion):
aperture = CircularAnnulus(
region.center.xy,
region.inner_radius, region.outer_radius)
elif isinstance(region, CircleAnnulusSkyRegion):
aperture = SkyCircularAnnulus(
region.center,
region.inner_radius, region.outer_radius)
elif isinstance(region, EllipseAnnulusPixelRegion):
aperture = EllipticalAnnulus(
region.center.xy,
region.inner_width * 0.5, region.outer_width * 0.5,
region.outer_height * 0.5, b_in=region.inner_height * 0.5,
theta=region.angle.to_value(u.radian))
elif isinstance(region, EllipseAnnulusSkyRegion):
aperture = SkyEllipticalAnnulus(
region.center,
region.inner_width * 0.5, region.outer_width * 0.5,
region.outer_height * 0.5, b_in=region.inner_height * 0.5,
theta=(region.angle - (90 * u.deg)))
elif isinstance(region, RectangleAnnulusPixelRegion):
aperture = RectangularAnnulus(
region.center.xy,
region.inner_width, region.outer_width,
region.outer_height, h_in=region.inner_height,
theta=region.angle.to_value(u.radian))
elif isinstance(region, RectangleAnnulusSkyRegion):
aperture = SkyRectangularAnnulus(
region.center,
region.inner_width, region.outer_width,
region.outer_height, h_in=region.inner_height,
theta=(region.angle - (90 * u.deg)))
else:
raise TypeError(f'Cannot convert {region.__class__.__name__!r} to '
'an Aperture object')
return aperture
