Compute the coordinates of an ellipse placed at a given latitude and longitude.
`coord` = MakeEllipseCoord (`lat`, `lon`, `dec`, `a_theta`, `b_theta`, [`cinterval`])
coord
:float, dimension(360/cinterval
, 2)
: The latitude [:,0] and longitude [:,1] coordinates of the ellipse in degrees.
lat
: float
: The latitude of the center of the ellipse in degrees.
lon
: float
: The longitude of the center of the ellipse in degrees.
dec
: float
: Rotation angle of the semi-major axis of the ellipse in degrees with respect to local north.
a_theta
: float
: The angular radius of the semi-major axis of the ellipse in degrees.
b_theta
: float
: The angular radius of the semi-minor axis of the ellipse in degrees.
cinterval
: optional, float, default = 1
: Angular spacing in degrees of the output latitude and longitude points. If not present, the default is 1.
MakeEllipseCoord
will calculate the (lat, long) coordinates of an ellipse placed on a sphere at position (lat
, lon
). The semi-major and semi-minor axes, expressed in angular radii in degrees, are given by a_theta
and b_theta
, respectively. The semimajor axis of the ellipse is initially directed due north, and it is then rotated clockwise by the angle dec
. This is useful for plotting ellipses on geographic maps. The first index in the output vectors corresponds to the northern rotated semimajor axis, and subsequent points are arranged in a clockwise manner. Input and output units are in degrees.