def test_hyperbolic_orbital_parameters(self):
# Unlike the elliptical test, this tests our favourite extra-solar
# visitor to make sure we can calculate Keplerian orbital
# characteristics from its orbital state vectors! That's right, we're
# talking about Sedna! The expected values are arrived at through
# calculation, and also
# http://orbitsimulator.com/formulas/OrbitalElements.html
physics_state = common.load_savefile(
common.savefile('tests/sedna.json'))
sun = physics_state[0]
oumuamua = physics_state[1]
expected_semimajor_axis = -71231070.14146987
self.assertAlmostEqual(calc.semimajor_axis(oumuamua, sun),
expected_semimajor_axis,
delta=abs(0.01 * expected_semimajor_axis))
expected_eccentricity = 1644.477
self.assertAlmostEqual(calc.fastnorm(calc.eccentricity(oumuamua, sun)),
expected_eccentricity,
delta=0.01 * expected_eccentricity)
expected_periapsis = 1.1714e11 # Through calculation
self.assertAlmostEqual(calc.periapsis(sun, oumuamua) + oumuamua.r,
expected_periapsis,
delta=0.01 * 78989185420.15271)
def test_elliptical_orbital_parameters(self):
# Again, see
# https://www.wolframalpha.com/input/?i=International+Space+Station
# For these expected values
physics_state = common.load_savefile(
common.savefile('tests/gui-test.json'))
iss = physics_state[0]
earth = physics_state[1]
# The semiaxes are relatively close to expected.
self.assertAlmostEqual(calc.semimajor_axis(iss, earth),
6785e3,
delta=0.01 * earth.r)
# The eccentricity is within 1e-6 of the expected.
self.assertAlmostEqual(calc.fastnorm(calc.eccentricity(iss, earth)),
5.893e-4,
delta=1e-3)
# The apoapsis is relatively close to expected.
self.assertAlmostEqual(calc.apoapsis(iss, earth),
418.3e3,
delta=0.01 * earth.r)
# The periapsis is relatively close to expected.
self.assertAlmostEqual(calc.periapsis(iss, earth),
410.3e3,
delta=0.01 * earth.r)
def _create_wtexts(self):
vpython.canvas.get_selected().caption += "<table>\n"
self._wtexts: List[TableText] = []
self._wtexts.append(
TableText("Simulation time",
lambda state: datetime.fromtimestamp(
state.timestamp, common.TIMEZONE).strftime('%x %X'),
"Current time in simulation",
new_section=False))
self._wtexts.append(
TableText("Orbit speed",
lambda state: common.format_num(
calc.orb_speed(state.craft_entity(),
state.reference_entity()), " m/s"),
"Speed required for circular orbit at current altitude",
new_section=False))
self._wtexts.append(
TableText(
"Periapsis",
lambda state: common.format_num(calc.periapsis(
state.craft_entity(), state.reference_entity()) / 1000,
" km",
decimals=3),
"Lowest altitude in naïve orbit around reference",
new_section=False))
self._wtexts.append(
TableText(
"Apoapsis",
lambda state: common.format_num(calc.apoapsis(
state.craft_entity(), state.reference_entity()) / 1000,
" km",
decimals=3),
"Highest altitude in naïve orbit around reference",
new_section=False))
self._wtexts.append(
TableText(
# The H in HRT stands for Habitat, even though craft is more
# general and covers Ayse, but HRT is the familiar triple name and
# the Hawking III says trans rights.
"HRT phase θ",
lambda state: common.format_num(
calc.phase_angle(
state.craft_entity(), state.reference_entity(),
state.target_entity()), "°") or "Same ref and targ",
"Angle between Habitat, Reference, and Target",
new_section=False))
self._wtexts.append(
TableText(
"Throttle",
lambda state: "{:.1%}".format(state.craft_entity().throttle),
"Percentage of habitat's maximum rated engines",
new_section=True))
self._wtexts.append(
TableText("Engine Acceleration",
lambda state: common.format_num(
calc.engine_acceleration(state), " m/s/s") +
(' [SRB]' if state.srb_time > 0 else ''),
"Acceleration due to craft's engine thrust",
new_section=False))
self._wtexts.append(
TableText("Drag",
lambda state: common.format_num(
calc.fastnorm(calc.drag(state)), " m/s/s"),
"Atmospheric drag acting on the craft",
new_section=False))
self._wtexts.append(
TableText("Fuel",
lambda state: common.format_num(
state.craft_entity().fuel, " kg"),
"Remaining fuel of craft",
new_section=False))
def rotation_formatter(state: PhysicsState) -> str:
deg_spin = round(np.degrees(state.craft_entity().spin), ndigits=1)
if deg_spin < 0:
return f"{-deg_spin} °/s cw"
elif deg_spin > 0:
return f"{deg_spin} °/s ccw"
else:
return f"{deg_spin} °/s"
self._wtexts.append(
TableText("Rotation",
rotation_formatter,
"Rotation speed of craft",
new_section=False))
self._wtexts.append(
TableText(
"Ref altitude",
lambda state: common.format_num(calc.altitude(
state.craft_entity(), state.reference_entity()) / 1000,
" km",
decimals=3),
"Altitude of habitat above reference surface",
new_section=True))
self._wtexts.append(
TableText("Ref speed",
lambda state: common.format_num(
calc.speed(state.craft_entity(),
state.reference_entity()), " m/s"),
"Speed of habitat above reference surface",
new_section=False))
self._wtexts.append(
TableText(
"Vertical speed",
lambda state: common.format_num(
calc.v_speed(state.craft_entity(), state.reference_entity(
)), " m/s "),
"Vertical speed of habitat towards/away reference surface",
new_section=False))
self._wtexts.append(
TableText("Horizontal speed",
lambda state: common.format_num(
calc.h_speed(state.craft_entity(),
state.reference_entity()), " m/s "),
"Horizontal speed of habitat across reference surface",
new_section=False))
self._wtexts.append(
TableText("Pitch θ",
lambda state: common.format_num(
np.degrees(
calc.pitch(state.craft_entity(
), state.reference_entity())) % 360, "°"),
"Horizontal speed of habitat across reference surface",
new_section=False))
self._wtexts.append(
TableText("Targ altitude",
lambda state: common.format_num(calc.altitude(
state.craft_entity(), state.target_entity()) / 1000,
" km",
decimals=3),
"Altitude of habitat above reference surface",
new_section=True))
self._wtexts.append(
TableText("Targ speed",
lambda state: common.format_num(
calc.speed(state.craft_entity(), state.target_entity(
)), " m/s"),
"Speed of habitat above target surface",
new_section=False))
self._wtexts.append(
TableText(
"Landing acc",
lambda state: common.format_num(
calc.landing_acceleration(state.craft_entity(),
state.target_entity()), " m/s/s"
) or "no vertical landing",
"Constant engine acc to land during vertical descent to target",
new_section=False))
vpython.canvas.get_selected().caption += "</table>"
