semi_circular_loop#

synthesizAR.models.semi_circular_loop(length: Unit('cm') = None, s: Unit('cm') = None, observer=None, obstime=None, n_points=1000, offset: Unit('cm') = None, gamma: Unit('deg') = <Quantity 0. deg>, inclination: Unit('deg') = <Quantity 0. deg>, ellipticity=0, correct_z=True)[source]#

Generate coordinates for a semi-circular loop

Parameters:

  • length (Quantity) – Full length of the loop

  • s (Quantity) – Field-aligned coordinate. If specifying s directly, do not specify length

  • observer (SkyCoord, optional) – Observer that defines te HCC coordinate system. Effectively, this is the coordinate of the midpoint of the loop.

  • obstime (parsable by Time, optional) – Observation time of the HCC frame. If None, will default to the obstime of the observer.

  • n_points (int, optional) – Number of points in the coordinate. Only used if s is not specified.

  • offset (Quantity, optional) – Offset in the direction perpendicular and parallel to loop, convenient for simulating arcade geometries. This should always be of length 2.

  • gamma (Quantity, optional) – Angle between the loop axis and the HCC x-axis. This defines the orientation of the loop in the HCC x-y plane. gamma=0 corresponds to a loop who’s axis is perpendicular to the HCC y-axis.

  • inclination (Quantity, optional) – Angle between the HCC z-axis and the loop plane. An inclination of 0 corresponds to a loop that extends vertically only in the z-direction while an inclination of 90 degrees corresponds to a loop that lies entirely in the HCC x-y plane.

  • ellipticity (float, optional) – Must be between -1 and +1. If > 0, the loop will be “tall and skinny” and if < 0, the loop will be “short and fat”. Note that if this value is nonzero, length is no longer the actual loop length because the loop is no longer semi-circular.

  • correct_z (bool, optional) – If True, correct the z-coordinate such that the footpoint lies on the surface of the Sun. This does not correct the coordinate such that the strand is normal to the surface at the footpoint.