x_axis)
else:
rot_matrix_list = [
_make_rotation_matrix_from_reprs(vect, x_axis)
for vect in hgs_x_axis_detilt
]
rot_matrix = np.stack(rot_matrix_list)
return matrix_product(rot_matrix, _SUN_DETILT_MATRIX)
@frame_transform_graph.transform(DynamicMatrixTransform,
HeliographicStonyhurst, HCRS)
def hgs_to_hcrs(hgscoord, hcrsframe):
"""
Convert from Heliographic Stonyhurst to HCRS.
"""
return matrix_transpose(hcrs_to_hgs(hcrsframe, hgscoord))
@frame_transform_graph.transform(FunctionTransform, HeliographicStonyhurst,
HeliographicStonyhurst)
def hgs_to_hgs(from_coo, to_frame):
if np.all(from_coo.obstime == to_frame.obstime):
return to_frame.realize_frame(from_coo.data)
else:
return from_coo.transform_to(HCRS).transform_to(to_frame)
__doc__ += _make_transform_graph_docs()
earth_pos_icrs = get_body_barycentric('earth', hgsframe.obstime)
sun_earth = earth_pos_icrs - sun_pos_icrs
# De-tilt the Sun-Earth vector to the frame with the Sun's rotation axis parallel to the Z axis
sun_earth_detilt = sun_earth.transform(_SUN_DETILT_MATRIX)
# Remove the component of the Sun-Earth vector that is parallel to the Sun's north pole
# (The additional transpose operations are to handle both scalar and array obstime situations)
hgs_x_axis_detilt = CartesianRepresentation((sun_earth_detilt.xyz.T * [1, 1, 0]).T)
# The above vector, which is in the Sun's equatorial plane, is also the X axis of HGS
x_axis = CartesianRepresentation(1, 0, 0)
if hgsframe.obstime.isscalar:
rot_matrix = _make_rotation_matrix_from_reprs(hgs_x_axis_detilt, x_axis)
else:
rot_matrix_list = [_make_rotation_matrix_from_reprs(vect, x_axis) for vect in hgs_x_axis_detilt]
rot_matrix = np.stack(rot_matrix_list)
return matrix_product(rot_matrix, _SUN_DETILT_MATRIX)
@frame_transform_graph.transform(DynamicMatrixTransform, HeliographicStonyhurst, HCRS)
def hgs_to_hcrs(hgscoord, hcrsframe):
"""
Convert from Heliographic Stonyhurst to HCRS.
"""
return matrix_transpose(hcrs_to_hgs(hcrsframe, hgscoord))
__doc__ += _make_transform_graph_docs()