poliastro.core.util

Module Contents

Functions

rotation_matrix(angle, axis)
alinspace(start, stop=None, num=50, endpoint=True)	Return increasing, evenly spaced angular values over a specified interval.
spherical_to_cartesian(v)	Compute cartesian coordinates from spherical coordinates (norm, colat, long). This function is vectorized.
planetocentric_to_AltAz(theta, phi)	Defines transformation matrix to convert from Planetocentric coordinate system

poliastro.core.util.rotation_matrix(angle, axis)

poliastro.core.util.alinspace(start, stop=None, num=50, endpoint=True)

Return increasing, evenly spaced angular values over a specified interval.

poliastro.core.util.spherical_to_cartesian(v)

Compute cartesian coordinates from spherical coordinates (norm, colat, long). This function is vectorized.

\[\begin{split}v = norm \cdot \begin{bmatrix} \sin(colat)\cos(long)\\ \sin(colat)\sin(long)\\ \cos(colat)\\ \end{bmatrix}\end{split}\]

Parameters

v (numpy.ndarray) – Spherical coordinates in 3D (norm, colat, long). Angles must be in radians.

Returns

v – Cartesian coordinates (x,y,z)

Return type

numpy.ndarray

poliastro.core.util.planetocentric_to_AltAz(theta, phi)

Defines transformation matrix to convert from Planetocentric coordinate system to the Altitude-Azimuth system.

\[\begin{split}t\_matrix = \begin{bmatrix} -\sin(theta) & \cos(theta) & 0\\ -\sin(phi)\cdot\cos(theta) & -\sin(phi)\cdot\sin(theta) & \cos(phi)\\ \cos(phi)\cdot\cos(theta) & \cos(phi)\cdot\sin(theta) & \sin(phi) \end{bmatrix}\end{split}\]

Parameters

• theta (float) – Local sidereal time

• phi (float) – Planetodetic latitude

Returns

t_matrix – Transformation matrix

Return type

numpy.ndarray