coordinate_utility
- spherical_2_cartesian(r, phi, theta[, units='degree'])
Converts spherical polar coordinates into cartesian coordinates.
- Parameters:
r (array) – Radial distance.
phi (array) – Longitudinal coordinates.
theta (array) – Latitude coordinates.
units (str) – Units of
phi
andtheta
given in either ‘degrees’ or ‘radians’.
- Returns:
x, y, z (array) : cartesian coordinates.
- celestial_2_cartesian(r, ra, dec[, units='degree', output='both'])
Converts celestial spherical polar coordinates into cartesian coordinates.
- Parameters:
r (array) – Radial distance.
ra (array) – Longitudinal celestial coordinates.
dec (array) – Latitudinal celestial coordinates.
units (str) – Units of
ra
anddec
given in either ‘degrees’ or ‘radians’.output (str) – ‘euclidean’ or ‘both’. Determines whether to output only the euclidean or both euclidean and spherical coordinates.
- Returns:
Returns tuple of either:
phi, theta (array) – spherical polar coordinates.
x, y, z (array) – cartesian coordinates.
- spherical_2_unit_sphere(phi, theta[, units='degrees'])
Project coordinates across a sphere (or on the sky) into cartesian coordinates on a unit sphere.
- Parameters:
r (array) – Radial distance.
phi (array) – Longitudinal coordinates.
theta (array) – Latitudinal coordinates.
units (str) – Units of
ra
anddec
given in either ‘degrees’ or ‘radians’.
- Returns:
x, y, z (array) : cartesian coordinates.
- celestial_2_unit_sphere(ra, dec[, units='degrees', output='both'])
Project celestial coordinates on a sphere into cartesian coordinates on a unit sphere.
- Parameters:
r (array) – Radial distance.
ra (array) – Longitudinal celestial coordinates.
dec (array) – Latitudinal celestial coordinates.
units (str) – Units of
ra
anddec
given in either ‘degrees’ or ‘radians’.output (str) – ‘euclidean’ or ‘both’. Determines whether to output only the euclidean or both euclidean and spherical coordinates.
- Returns:
Returns tuple of either:
phi, theta (array) – spherical polar coordinates.
x, y, z (array) – cartesian coordinates.
- perpendicular_distance_2_angle(distance)
Converts distances across a unit sphere to angular distances.
- Parameters:
distance (array) – Perpendicular distances across (i.e. going on the surface) a unit sphere.
- Returns:
angular_distance (array) – The angular distance between points across a unit sphere.