get_rectangle_coordinates

sunpy.coordinates.utils.get_rectangle_coordinates(bottom_left, *, top_right=None, width: Unit(‘deg’) = None, height: Unit(‘deg’) = None)[source]

Specify a rectangular region of interest in longitude and latitude in a given coordinate frame.

Parameters
  • bottom_left (BaseCoordinateFrame or SkyCoord) – The bottom-left coordinate of the rectangle. Supports passing both the bottom left and top right coordinates by passing with a shape of (2,).

  • top_right (BaseCoordinateFrame or SkyCoord) – The top-right coordinate of the rectangle. If in a different frame than bottom_left and all required metadata for frame conversion is present, top_right will be transformed to bottom_left frame.

  • width (Quantity) – The width of the rectangle. Must be omitted if the coordinates of both corners have been specified.

  • height (Quantity) – The height of the rectangle. Must be omitted if the coordinates of both corners have been specified.

Returns

Examples

>>> import astropy.units as u
>>> from astropy.coordinates import SkyCoord
>>> from sunpy.coordinates.frames import HeliographicStonyhurst
>>> from sunpy.coordinates.utils import get_rectangle_coordinates
>>> # With bottom left as a SkyCoord, width and height
>>> bottom_left = SkyCoord(0 * u.arcsec, 0 * u.arcsec, frame='heliographic_stonyhurst')
>>> width = 10 * u.arcsec
>>> height = 10 * u.arcsec
>>> bottom_left, top_right = get_rectangle_coordinates(bottom_left, width=width, height=height)
>>> # With bottom left of shape (2,)
>>> bottom_left_vector = SkyCoord([0 * u.arcsec, 10 * u.arcsec], [0 * u.arcsec, 10 * u.arcsec], frame='heliographic_stonyhurst')
>>> bottom_left, top_right = get_rectangle_coordinates(bottom_left_vector)
>>> # With bottom left as a BaseCoordinateFrame instance, width and height
>>> bottom_left =  HeliographicStonyhurst(0 * u.arcsec, 0 * u.arcsec)
>>> width = 10 * u.arcsec
>>> height = 10 * u.arcsec
>>> bottom_left, top_right = get_rectangle_coordinates(bottom_left, width=width, height=height)

Notes

width is always treated as an increase in longitude, but bottom_left may have a higher value of longitude than top_right due to the wrapping of the longitude angle. Appropriate care should be taken when using this function’s output to define a range of longitudes.

height is always treated as an increase in latitude, but this function does not enforce that bottom_left has a lower value of latitude than top_right, in case that orientation is valid for the intended use.