ENH: Events Class and Flight Rework

.pylintrc

@@ -356,7 +356,7 @@ max-public-methods=25
 max-returns=25
 
 # Maximum number of statements in function / method body.
-max-statements=25
+max-statements=50
 
 # Minimum number of public methods for a class (see R0903).
 min-public-methods=0
@@ -481,6 +481,7 @@ disable=raw-checker-failed,
         use-symbolic-message-instead,
         use-implicit-booleaness-not-comparison-to-string,
         use-implicit-booleaness-not-comparison-to-zero,
+        use-implicit-booleaness-not-comparison, # explicit == [] is clearer, esp. in tests
         no-else-return, # this is a style preference, we don't need to follow it
         inconsistent-return-statements,
         unspecified-encoding, # this is not a relevant issue.

CHANGELOG.md

@@ -39,10 +39,13 @@ Attention: The newest changes should be on top -->
 
 ### Changed
 
-- 
+- ENH: store the flight solution as one flat list of rows. `PhaseSolution` no longer holds rows and becomes internal as `_PhaseSolution`: it describes a phase and records where its rows begin. Per-phase reads move to `Solution.phase_rows`, `phase_time`, `phase_series`, `phase_canonical_array` and `phase_post`. `Solution.canonical_states`, `last_row` and `+=` are removed. Saved solutions store the rows once for the whole flight. The pre-`Solution` format, a bare list of rows, still loads.
+- ENH: keep the post-process values recorded during a simulation on the `Solution`, beside the row they were computed from, so a rollback can no longer leave them on a different time grid from the states. `_PhaseDynamics.post_process_row` becomes `post_process_values` and no longer returns the time.
+- ENH: replace the `state_history` event kwarg with `previous_state` / `previous_time`, both gated behind `needs`. Read the trajectory itself from `kwargs["flight"].solution`. Legacy positional controller functions now take 5, 6 or 7 arguments instead of 6, 7 or 8, since `state_history` is no longer passed as the 4th.
 
 ### Fixed
 
+- BUG: read the last state through the flight phase that owns it, rather than the phase being flown, when starting a new phase. The two differ when a phase ends without taking a solver step.
 - BUG: Add wraparound logic for wind direction in environment plots [#939](https://github.com/RocketPy-Team/RocketPy/pull/939)
 
 ## [v1.12.1] - 2026-04-03

docs/development/testing.rst

@@ -255,8 +255,6 @@ Consider the following integration test:
         example_plain_env : rocketpy.Environment
             Example environment object to be tested.
         """
-        # TODO:: this should be added to the set_atmospheric_model() method as a
-        #        "file" option, instead of receiving the URL as a string.
         URL = "http://weather.uwyo.edu/cgi-bin/sounding?region=samer&TYPE=TEXT%3ALIST&YEAR=2019&MONTH=02&FROM=0500&TO=0512&STNM=83779"
         # give it at least 5 times to try to download the file
         example_plain_env.set_atmospheric_model(type="wyoming_sounding", file=URL)

docs/examples/bella_lui_flight_sim.ipynb

@@ -432,7 +432,6 @@
     "    trigger=\"apogee\",\n",
     "    sampling_rate=105,\n",
     "    lag=parameters.get(\"lag_rec\")[0],\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")"
    ]
   },

docs/examples/genesis_flight_sim.ipynb

@@ -277,7 +277,6 @@
     "    trigger=\"apogee\",\n",
     "    sampling_rate=105,\n",
     "    lag=1,\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")\n",
     "\n",
     "Main = GENESIS.add_parachute(\n",
@@ -286,7 +285,6 @@
     "    trigger=870,\n",
     "    sampling_rate=105,\n",
     "    lag=1,\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")"
    ]
   },

docs/examples/hedy_flight_sim.ipynb

@@ -804,13 +804,11 @@
     "main_trigger = rocket_config[\"parachutes\"][\"main\"][\"trigger\"]\n",
     "main_sampling_rate = rocket_config[\"parachutes\"][\"main\"][\"sampling_rate\"]\n",
     "main_lag = rocket_config[\"parachutes\"][\"main\"][\"lag\"]\n",
-    "main_noise = rocket_config[\"parachutes\"][\"main\"][\"noise\"]\n",
     "\n",
     "drogue_cd_s = rocket_config[\"parachutes\"][\"drogue\"][\"cd_s\"]\n",
     "drogue_trigger = rocket_config[\"parachutes\"][\"drogue\"][\"trigger\"]\n",
     "drogue_sampling_rate = rocket_config[\"parachutes\"][\"drogue\"][\"sampling_rate\"]\n",
     "drogue_lag = rocket_config[\"parachutes\"][\"drogue\"][\"lag\"]\n",
-    "drogue_noise = rocket_config[\"parachutes\"][\"drogue\"][\"noise\"]\n",
     "\n",
     "parachutes = {}\n",
     "\n",
@@ -820,7 +818,6 @@
     "    trigger=main_trigger,\n",
     "    sampling_rate=main_sampling_rate,\n",
     "    lag=main_lag,\n",
-    "    noise=main_noise,\n",
     ")\n",
     "\n",
     "parachutes[1] = Parachute(\n",
@@ -829,7 +826,6 @@
     "    trigger=drogue_trigger,\n",
     "    sampling_rate=drogue_sampling_rate,\n",
     "    lag=drogue_lag,\n",
-    "    noise=drogue_noise,\n",
     ")"
    ]
   },

docs/examples/juno3_flight_sim.ipynb

@@ -342,7 +342,6 @@
     "    cd_s=0.885,\n",
     "    trigger=\"apogee\",\n",
     "    sampling_rate=105,\n",
-    "    noise=(0, 8.3, 0.5),\n",
     "    lag=0.5,\n",
     ")"
    ]

docs/examples/lince_flight_sim.ipynb

@@ -263,7 +263,7 @@
    "outputs": [],
    "source": [
     "Main = LincePreDeploy.add_parachute(\n",
-    "    \"Main\", cd_s=3.9, trigger=\"apogee\", sampling_rate=150, lag=0, noise=(0, 0, 0)\n",
+    "    \"Main\", cd_s=3.9, trigger=\"apogee\", sampling_rate=150, lag=0\n",
     ")"
    ]
   },
@@ -326,7 +326,7 @@
    "outputs": [],
    "source": [
     "Main_stage_1 = LincePostDeploy.add_parachute(\n",
-    "    \"Main\", cd_s=3.9, trigger=\"apogee\", sampling_rate=150, lag=0, noise=(0, 0, 0)\n",
+    "    \"Main\", cd_s=3.9, trigger=\"apogee\", sampling_rate=150, lag=0\n",
     ")"
    ]
   },
@@ -394,7 +394,7 @@
    "outputs": [],
    "source": [
     "Main_stage_2 = Payload.add_parachute(\n",
-    "    \"Main\", cd_s=0.159248, trigger=\"apogee\", sampling_rate=150, lag=0, noise=(0, 0, 0)\n",
+    "    \"Main\", cd_s=0.159248, trigger=\"apogee\", sampling_rate=150, lag=0\n",
     ")"
    ]
   },

docs/examples/ndrt_2020_flight_sim.ipynb

@@ -377,15 +377,13 @@
     "    trigger=\"apogee\",\n",
     "    sampling_rate=105,\n",
     "    lag=parameters.get(\"lag_rec\")[0],\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")\n",
     "main = ndrt2020.add_parachute(\n",
     "    \"Main\",\n",
     "    cd_s=parameters.get(\"cd_s_main\")[0],\n",
     "    trigger=167.64,\n",
     "    sampling_rate=105,\n",
     "    lag=parameters.get(\"lag_rec\")[0],\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")"
    ]
   },

docs/examples/valetudo_flight_sim.ipynb

@@ -393,7 +393,6 @@
     "    trigger=\"apogee\",\n",
     "    sampling_rate=105,\n",
     "    lag=parameters.get(\"lag_rec\")[0],\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")"
    ]
   },

docs/notebooks/getting_started_colab.ipynb

@@ -491,7 +491,6 @@
     "    trigger=800,\n",
     "    sampling_rate=105,\n",
     "    lag=1.5,\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")\n",
     "\n",
     "Drogue = calisto.add_parachute(\n",
@@ -500,7 +499,6 @@
     "    trigger=\"apogee\",\n",
     "    sampling_rate=105,\n",
     "    lag=1.5,\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")"
    ]
   },
@@ -588,13 +586,7 @@
    "execution_count": null,
    "metadata": {},
    "outputs": [],
-   "source": [
-    "test_flight.export_kml(\n",
-    "    file_name=\"trajectory.kml\",\n",
-    "    extrude=True,\n",
-    "    altitude_mode=\"relative_to_ground\",\n",
-    ")"
-   ]
+   "source": "test_flight.exports.kml(\n    file_name=\"trajectory.kml\",\n    extrude=True,\n    altitude_mode=\"relative_to_ground\",\n)"
   },
   {
    "attachments": {},
@@ -824,4 +816,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 2
-}
+}

docs/notebooks/monte_carlo_analysis/monte_carlo_analysis.ipynb

@@ -369,7 +369,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": null,
    "metadata": {
     "colab": {
      "base_uri": "https://localhost:8080/",
@@ -416,14 +416,6 @@
     ")\n",
     "\n",
     "\n",
-    "# Set up parachutes. This rocket, named Valetudo, only has a drogue chute.\n",
-    "def drogue_trigger(p, h, y):\n",
-    "    # Check if rocket is going down, i.e. if it has passed the apogee\n",
-    "    vertical_velocity = y[5]\n",
-    "    # Return true to activate parachute once the vertical velocity is negative\n",
-    "    return True if vertical_velocity < 0 else False\n",
-    "\n",
-    "\n",
     "# Iterate over flight settings\n",
     "out = display(\"Starting\", display_id=True)\n",
     "for setting in flight_settings(analysis_parameters, number_of_simulations):\n",
@@ -498,10 +490,9 @@
     "    Drogue = Valetudo.add_parachute(\n",
     "        \"Drogue\",\n",
     "        cd_s=setting[\"cd_s_drogue\"],\n",
-    "        trigger=drogue_trigger,\n",
+    "        trigger=\"apogee\",\n",
     "        sampling_rate=105,\n",
     "        lag=setting[\"lag_rec\"] + setting[\"lag_se\"],\n",
-    "        noise=(0, 8.3, 0.5),\n",
     "    )\n",
     "\n",
     "    # Run trajectory simulation\n",

docs/notebooks/monte_carlo_analysis/monte_carlo_class_usage.ipynb

@@ -186,7 +186,6 @@
     "    trigger=800,\n",
     "    sampling_rate=105,\n",
     "    lag=1.5,\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")\n",
     "\n",
     "Drogue = rocket.add_parachute(\n",
@@ -195,7 +194,6 @@
     "    trigger=\"apogee\",\n",
     "    sampling_rate=105,\n",
     "    lag=1.5,\n",
-    "    noise=(0, 8.3, 0.5),\n",
     ")\n",
     "\n",
     "# Flight\n",

docs/notebooks/monte_carlo_analysis/monte_carlo_sensitivity_simulation.py

@@ -141,7 +141,6 @@
     lag=analysis_parameters["parachutes_main_lag"]["mean"],
     trigger=800,
     sampling_rate=105,
-    noise=(0, 8.3, 0.5),
 )
 
 Drogue = rocket.add_parachute(
@@ -150,7 +149,6 @@
     lag=analysis_parameters["parachutes_drogue_lag"]["mean"],
     trigger="apogee",
     sampling_rate=105,
-    noise=(0, 8.3, 0.5),
 )
 
 # Flight

docs/notebooks/monte_carlo_analysis/parachute_drop_from_helicopter.ipynb

@@ -423,14 +423,6 @@
     ")\n",
     "\n",
     "\n",
-    "# Set up parachutes. This rocket, named Valetudo, only has a drogue chute.\n",
-    "def drogueTrigger(p, h, y):\n",
-    "    # Check if rocket is going down, i.e. if it has passed the apogee\n",
-    "    vertical_velocity = y[5]\n",
-    "    # Return true to activate parachute once the vertical velocity is negative\n",
-    "    return True if vertical_velocity < 0 else False\n",
-    "\n",
-    "\n",
     "# Iterate over flight settings\n",
     "out = display(\"Starting\", display_id=True)\n",
     "for setting in flight_settings(analysis_parameters, number_of_simulations):\n",
@@ -496,10 +488,9 @@
     "    Drogue = Valetudo.addParachute(\n",
     "        \"Drogue\",\n",
     "        CdS=setting[\"CdSDrogue\"],\n",
-    "        trigger=drogueTrigger,\n",
+    "        trigger=\"apogee\",\n",
     "        samplingRate=105,\n",
     "        lag=setting[\"lag_rec\"] + setting[\"lag_se\"],\n",
-    "        noise=(0, 8.3, 0.5),\n",
     "    )\n",
     "\n",
     "    # Run trajectory simulation\n",

docs/reference/classes/Event.rst

@@ -0,0 +1,5 @@
+Event Class
+-----------
+
+.. autoclass:: rocketpy.Event
+   :members:

docs/reference/classes/Solution.rst

@@ -0,0 +1,57 @@
+Solution Classes
+----------------
+
+These classes hold the state history produced by a :class:`rocketpy.Flight`
+simulation. They are not part of RocketPy's top-level namespace; a flight's
+solution is reached through :attr:`Flight.solution <rocketpy.Flight.solution>`.
+
+The ``Solution`` holds every row of the flight in one list, in the order they
+were flown. The flight phases sit alongside it, each saying where its own rows
+begin. So a row is read from the solution, and a phase tells you what that row
+means::
+
+    for index, phase in enumerate(flight.solution.phases):
+        start, stop = flight.solution.phase_span(index)
+        print(phase.name, stop - start)
+
+:meth:`Solution.phase_span` gives where a phase's rows begin and end, so
+``flight.solution[start:stop]``, ``flight.solution["vz"][start:stop]`` and
+``flight.solution.canonical_array[start:stop]`` read just that phase.
+
+.. autoclass:: rocketpy.simulation.solution.Solution
+   :members:
+
+Post-process variables
+~~~~~~~~~~~~~~~~~~~~~~
+
+On its way to each state derivative, a flight phase works out quantities it
+never integrates: the accelerations, the aerodynamic forces and moments, and
+the net thrust. Read them through ``flight.solution.post``::
+
+    post = flight.solution.post
+    post.names             # every variable this flight computes
+    post["az"]             # its [t, value] history over the whole flight
+    post.at(3.0)           # every variable at the nearest stored time
+
+The same values back the flight's own :attr:`Flight.az <rocketpy.Flight.az>`
+and its companions, which wrap them as a
+:class:`Function <rocketpy.Function>` so they can be plotted and evaluated at
+any time. Reach for ``post`` when you want the values exactly as the simulation
+stored them, without interpolation.
+
+.. autoclass:: rocketpy.simulation.solution.PostProcessSolution
+   :members:
+
+The phase objects themselves are internal to RocketPy for now, so their shape
+may change between releases. These are the values worth reading off one:
+
+``name``
+    The phase's name, such as ``"rail"`` or ``"free_flight"``.
+``t_start``
+    The time the phase began, in seconds.
+``start``
+    Where the phase's first row sits in the solution's rows.
+``dynamics.states``
+    The states the phase integrated, in the order it stored them.
+``dynamics.name``
+    The kind of phase it was.

docs/reference/classes/sensors/accelerometer.rst

@@ -1,5 +1,5 @@
 Accelerometer Class
 -------------------
 
-.. autoclass:: rocketpy.sensors.Accelerometer
+.. autoclass:: rocketpy.Accelerometer
     :members:

docs/reference/classes/sensors/barometer.rst

@@ -1,5 +1,5 @@
 Barometer Class
 ---------------
 
-.. autoclass:: rocketpy.sensors.Barometer
+.. autoclass:: rocketpy.Barometer
     :members:

docs/reference/classes/sensors/gnss_receiver.rst

@@ -1,5 +1,5 @@
 GNSS Receiver Class
 -------------------
 
-.. autoclass:: rocketpy.sensors.GnssReceiver
+.. autoclass:: rocketpy.GnssReceiver
     :members:

docs/reference/classes/sensors/gyroscope.rst

@@ -1,5 +1,5 @@
 Gyroscope Class
 ---------------
 
-.. autoclass:: rocketpy.sensors.Gyroscope
+.. autoclass:: rocketpy.Gyroscope
     :members:

docs/reference/index.rst

@@ -16,6 +16,8 @@ This reference manual details functions, modules, methods and attributes include
    classes/Parachute
    classes/sensors/index.rst
    classes/Flight
+   classes/Solution
+   classes/Event
    Utilities <classes/utils/index>
    classes/EnvironmentAnalysis
    Monte Carlo Analysis <classes/monte_carlo/index> 

docs/technical/index.rst

@@ -17,6 +17,7 @@ in their code.
    Roll Moment <aerodynamics/roll_equations.rst>
    Sensitivity Analysis <sensitivity.rst>
    References <references.rst>
+   Simulation Loop <simulation_loop.rst>
 
 This section is still a work in progress, however, and not everything is documented yet.
 If you have any questions, please contact the maintainers of RocketPy.