Major rework using rocketpy

.vscode/launch.json

@@ -9,7 +9,8 @@
             "type": "debugpy",
             "request": "launch",
             "program": "testing.py",
-            "console": "integratedTerminal"
+            "console": "integratedTerminal",
+            "justMyCode": false
         }
     ]
 }

rework_test.py

@@ -0,0 +1,36 @@
+import cProfile
+import numpy as np
+import tqdm
+
+from spatz.simulation import Simulation
+from spatz.simulations.rocketpy import RocketPyCSV
+from spatz.sensors.pressure.ms5611 import MS5611
+from spatz.sensors.imu.wsen_isds import WSEN_ISDS_ACC, WSEN_ISDS_GYRO
+from spatz.sensors.imu.h3lis100dl import H3LIS100DL
+
+
+simulation = Simulation().load(RocketPyCSV('nominal_wind.csv'))
+
+barometer = simulation.add_sensor(MS5611)
+
+# Orientation matrix of the WSEN-ISDS IMU on the rocket.
+orientation = np.array([
+    [ 1,  0,  0],
+    [ 0,  0, -1],
+    [ 0, -1,  0]
+])
+accelerometer = simulation.add_sensor(WSEN_ISDS_ACC, orientation=orientation)
+gyroscope = simulation.add_sensor(WSEN_ISDS_GYRO)
+high_g = simulation.add_sensor(H3LIS100DL)
+
+
+for i in tqdm.tqdm(range(5000)):
+    simulation.advance(0.1)
+    pressure = barometer()
+    acc = accelerometer()
+    omegas = gyroscope()
+    g = high_g()
+
+
+df = simulation.get_logger().get_dataframe()
+df.to_csv('dummy2.csv')

spatz/logger.py

@@ -4,43 +4,7 @@ import pandas as pd
 from typing import Any, Tuple, List
 from numpy.typing import ArrayLike
 
-from abc import abstractmethod
-
-
-class Advanceable:
-    def __init__(self) -> None:
-        self.reset()
-
-    def step(self, dt: float):
-        """Advances the simulation data in time.
-
-        Args:
-            dt (float): The step in time to make.
-        """
-        self.__t += dt
-        self._on_step(dt)
-
-    def reset(self):
-        """
-        Reset the Avanceable object to its initial state.
-        """
-        self.__t = 0
-        self._on_reset()
-
-    @abstractmethod
-    def _on_step(self, dt: float):
-        pass
-
-    @abstractmethod
-    def _on_reset(self):
-        pass
-
-    def get_time(self) -> float:
-        """
-        Returns:
-            float: Returns the current time of the Advanceable.
-        """
-        return self.__t
+from spatz.simulations.advanceable import Advanceable
 
 
 class Logger(Advanceable):

spatz/sensors/__init__.py

@@ -1,6 +1,6 @@
 from spatz.sensors.sensor import Sensor
 from spatz.sensors.gps import GPS
-from spatz.sensors.imu import Accelerometer, Gyroscope, IMU
+from spatz.sensors.imu import Accelerometer, Gyroscope, IMU, CoordSystem
 from spatz.sensors.pressure import PressureSensor
 from spatz.sensors.temperature import TemperatureSensor
 from spatz.sensors.compound import CompoundSensor

spatz/sensors/imu/__init__.py

@@ -1,3 +1,3 @@
-from spatz.sensors.imu.accelerometer import Accelerometer
+from spatz.sensors.imu.accelerometer import Accelerometer, CoordSystem
 from spatz.sensors.imu.gyroscope import Gyroscope
 from spatz.sensors.imu.imu import IMU

spatz/sensors/imu/accelerometer.py

@@ -1,11 +1,13 @@
 import numpy as np
 
 from typing import List
-from numpy.typing import ArrayLike
+from enum import Enum
+from numpy.typing import ArrayLike, NDArray
 
 from spatz.sensors import Sensor
 from spatz.transforms import Transform
 from spatz.dataset import Dataset
+from spatz.simulations.data_source import DataSource
 from spatz.logger import Logger
 
 
@@ -18,33 +20,61 @@ __all__=[
 g = 9.81
 
 
+class CoordSystem:
+    LEFT_HANDED = 0,
+    RIGHT_HANDED = 0,
+
+
 class Accelerometer(Sensor):
-    def __init__(self, dataset: Dataset, logger: Logger, offset: float = 0, transforms: List[Transform] = []):
+    def __init__(
+            self, dataset: DataSource, 
+            logger: Logger, 
+            coord_system: CoordSystem = CoordSystem.RIGHT_HANDED,
+            orientation: NDArray = np.identity(3), 
+            offset: float = 0, 
+            transforms: List[Transform] = []):
+        """_summary_
+
+        Args:
+            dataset (Dataset): A dataset object to fetch data from.
+            logger (Logger): A logger object to write data to.
+            coord_system (CoordSystem, optional): The type of coordinate system to use. Defaults to CoordSystem.RIGHT_HANDED.
+            orientation (NDArray, optional): The orientation of the sensor inside the spacecraft. Defaults to np.identity(3).
+            offset (float, optional): The offset of the sensor from the origin around which the object rotates. Defaults to 0.
+            transforms (List[Transform], optional): A list of transformations applied to the sensor measurements. Defaults to [].
+        """
         super().__init__(dataset, logger, transforms)
 
+        assert orientation.shape == (3, 3), 'Orientation has to be a 3x3 matrix.'
+
         self._offset = np.array([offset, 0, 0])
+        self._coord_system = coord_system
+        self._orientation = orientation
 
     def _get_data(self) -> ArrayLike | float:
-        acc = self._dataset.get_acceleration(frame='FL')
+        acc = self._dataset.get_acceleration('global')
 
-        self._logger.write('FL_x', acc[0], self._get_name())
-        self._logger.write('FL_y', acc[1], self._get_name())
-        self._logger.write('FL_z', acc[2], self._get_name())
+        # self._logger.write('global_ax', acc[0], self._get_name())
+        # self._logger.write('global_ay', acc[1], self._get_name())
+        # self._logger.write('global_az', acc[2], self._get_name())
 
         # Convert FL to body
-        mat = self._dataset.launch_rail_to_body()
-        acc = mat @ acc
-        acc += mat @ np.array([0, 0, g])
+        acc = self._dataset.global_to_local() @ acc
+        # acc += mat @ np.array([0, 0, g])
 
-        self._logger.write('B_x', acc[0], self._get_name())
-        self._logger.write('B_y', acc[1], self._get_name())
-        self._logger.write('B_z', acc[2], self._get_name())
+        # self._logger.write('local_x', acc[0], self._get_name())
+        # self._logger.write('local_y', acc[1], self._get_name())
+        # self._logger.write('local_z', acc[2], self._get_name())
 
-        # Flip axes to sensor's perspective.
-        acc *= -1
+        # Flip axes to sensor's perspective. Spatz uses a right-handed coordinate system.
+        #if self._coord_system == CoordSystem.LEFT_HANDED:
+        #    acc[1] *= -1
+
+        # Rotate the acceleration vector to accomodate the accelerometer's orientation on the rocket.
+        acc = self._orientation @ acc
 
         # Add the effects of the imu's offset.
-        omega = self._dataset.get_angular_velocities()
+        omega = self._dataset.get_angular_velocity()
         acc += (np.cross(omega, self._offset) + np.cross(omega, np.cross(omega, self._offset)))
 
         return acc

spatz/sensors/imu/bmi088.py

@@ -0,0 +1,46 @@
+import numpy as np
+
+from typing import List, AnyStr
+
+from numpy.typing import ArrayLike
+from spatz.dataset import ArrayLike, Dataset
+from spatz.logger import ArrayLike, Logger
+from spatz.sensors import IMU, Accelerometer, Gyroscope, CoordSystem
+from spatz.transforms import Transform, GaussianNoise
+
+
+class BMI088(IMU):
+    def __init__(self, dataset: Dataset, logger: Logger, orientation = np.identity(3), offset=0, transforms: List[Transform] = []):
+        acc = BMI088Acc(dataset, logger, orientation, offset, transforms)
+        gyro = BMI088Gyro(dataset, logger, offset, transforms)
+
+        super().__init__(dataset, logger, acc, gyro, transforms)
+
+
+class BMI088Gyro(Gyroscope):
+    def __init__(self, dataset: Dataset, logger: Logger, offset: float = 0, transforms: List[Transform] = []):
+        super().__init__(dataset, logger, offset, transforms)
+
+    def _get_name(self) -> AnyStr:
+        return 'BMI088'
+
+    def _get_data(self) -> ArrayLike:
+        rots = self._dataset.fetch_values(['roll_l', 'pitch_l', 'yaw_l'])
+
+        return rots
+
+    def _sensor_specific_effects(self, x: ArrayLike) -> ArrayLike:
+        return x
+    
+
+class BMI088Acc(Accelerometer):
+    def __init__(self, dataset: Dataset, logger: Logger, orientation = np.identity(3), offset: float = 0, transforms: List[Transform] = []):
+        super().__init__(dataset, logger, CoordSystem.RIGHT_HANDED, orientation, offset, transforms)
+
+        self.__noise = GaussianNoise(0, 0.05)
+
+    def _get_name(self) -> AnyStr:
+        return 'BMI088'
+    
+    def _sensor_specific_effects(self, x: ArrayLike) -> ArrayLike:
+        return self.__noise(0, x)

spatz/sensors/imu/gyroscope.py

@@ -4,17 +4,18 @@ from typing import List
 from spatz.sensors import Sensor
 from spatz.transforms import Transform
 from spatz.dataset import Dataset
+from spatz.simulations.data_source import DataSource
 from spatz.logger import Logger
 
 
 class Gyroscope(Sensor):
-    def __init__(self, dataset: Dataset, logger: Logger, offset: float = 0, transforms: List[Transform] = []):
+    def __init__(self, dataset: DataSource, logger: Logger, offset: float = 0, transforms: List[Transform] = []):
         super().__init__(dataset, logger, transforms)
 
         self._offset = offset
 
     def _get_data(self) -> ArrayLike | float:
         # Rotation in rad/sec
-        x = self._dataset.get_angular_velocities()
+        x = self._dataset.get_angular_velocity()
 
         return x

spatz/sensors/imu/h3lis100dl.py

@@ -0,0 +1,30 @@
+import numpy as np
+
+from typing import List, AnyStr
+from numpy.core.numeric import identity as identity
+from numpy.typing import ArrayLike, NDArray
+
+from spatz.dataset import Dataset
+from spatz.simulations.data_source import DataSource
+from spatz.logger import Logger
+from spatz.sensors import Accelerometer, CoordSystem
+from spatz.transforms import Transform
+
+
+class H3LIS100DL(Accelerometer):
+    def __init__(self, dataset: DataSource, logger: Logger, orientation=np.identity(3), offset: float = 0, transforms: List[Transform] = []):        
+        super().__init__(dataset, logger, CoordSystem.RIGHT_HANDED, orientation, offset, transforms)
+
+    def _get_name(self) -> AnyStr:
+        return "H3LIS100DL"
+    
+    def _sensor_specific_effects(self, x: ArrayLike) -> ArrayLike:
+        # The sensor only measures values between -100g and +100g and in g/LSB.
+        g = 9.81
+        x = np.floor(np.clip(x, -100*g, +100*g) / g)
+
+        return x
+
+
+
+

spatz/sensors/imu/wsen_isds.py

@@ -3,8 +3,9 @@ import numpy as np
 from typing import AnyStr, List
 from numpy.typing import ArrayLike
 
-from spatz.sensors import Accelerometer, Gyroscope, IMU
+from spatz.sensors import Accelerometer, Gyroscope, IMU, CoordSystem
 from spatz.transforms import Transform, GaussianNoise
+from spatz.simulations.data_source import DataSource
 from spatz.dataset import Dataset
 from spatz.logger import Logger
 
@@ -14,8 +15,8 @@ class WSEN_ISDS(IMU):
 
 
 class WSEN_ISDS_ACC(Accelerometer):
-    def __init__(self, dataset: Dataset, logger: Logger, offset: float, transforms: List[Transform] = []):
-        super().__init__(dataset, logger, offset, transforms)
+    def __init__(self, dataset: DataSource, logger: Logger, orientation=np.identity(3), offset=0, transforms: List[Transform] = []):
+        super().__init__(dataset, logger, CoordSystem.LEFT_HANDED, orientation, offset, transforms)
 
         self.__variance = 0.05
         self.__noise = GaussianNoise(np.zeros(3), np.identity(3) * self.__variance)
@@ -35,11 +36,15 @@ class WSEN_ISDS_ACC(Accelerometer):
         self._logger.write('acc_y_noise', noise[1], self._get_name())
         self._logger.write('acc_z_noise', noise[2], self._get_name())
 
+        # The WSEN-ISDS accelerometer only measures acceleration between -16g and 16g. 
+        g = 9.81
+        y = np.clip(y, -16*g, +16*g)
+
         return y
     
 
 class WSEN_ISDS_GYRO(Gyroscope):
-    def __init__(self, dataset: Dataset, logger: Logger, offset: float, transforms: List[Transform] = []):
+    def __init__(self, dataset: Dataset, logger: Logger, offset=0, transforms: List[Transform] = []):
         super().__init__(dataset, logger, offset, transforms)
 
     def _get_name(self) -> AnyStr:
@@ -51,4 +56,8 @@ class WSEN_ISDS_GYRO(Gyroscope):
 
         # TODO: Noise model.
 
+        self._log('ox', x[0])
+        self._log('oy', x[1])
+        self._log('oz', x[2])
+
         return x

spatz/sensors/pressure/ms5611.py

@@ -3,12 +3,13 @@ from numpy.typing import ArrayLike
 
 from spatz.sensors import PressureSensor
 from spatz.dataset import Dataset, Phase
+from spatz.simulations.data_source import DataSource
 from spatz.logger import Logger
 from spatz.transforms import GaussianNoise, Transform, ProportionalGaussian
 
 
 class MS5611(PressureSensor):
-    def __init__(self, dataset: Dataset, logger: Logger, transforms: List[Transform] = [], ts_effects=True):
+    def __init__(self, dataset: DataSource, logger: Logger, transforms: List[Transform] = [], ts_effects=True):
         super().__init__(dataset, logger, transforms, ts_effects)
 
         # Noise model obtained by a test flight using this sensor.

spatz/sensors/pressure/pressure.py

@@ -6,11 +6,12 @@ from typing import List
 from spatz.sensors import Sensor
 from spatz.logger import Logger
 from spatz.dataset import Dataset
+from spatz.simulations.data_source import DataSource
 from spatz.transforms import Transform
 
 
 class PressureSensor(Sensor):
-    def __init__(self, dataset: Dataset, logger: Logger, transforms: List[Transform] = [], ts_effects=True, delay=0.0):
+    def __init__(self, dataset: DataSource, logger: Logger, transforms: List[Transform] = [], ts_effects=True, delay=0.0):
         """_summary_
 
         Args:
@@ -28,7 +29,7 @@ class PressureSensor(Sensor):
         self._ts_effects = active
 
     def _get_data(self) -> float:
-        x = self._dataset.get_pressure()
+        x = self._dataset.get_static_pressure()
 
         if self._ts_effects:
             # Pre-defined constants.
@@ -36,16 +37,16 @@ class PressureSensor(Sensor):
             sigma = 40
 
             # How far away from transsonic speed (mach 1) are we?
-            vvec = self._dataset.get_velocity()
+            vvec = self._dataset.get_velocity('global')
             dv = np.abs(np.linalg.norm(vvec) - self._dataset.get_speed_of_sound())
 
             # Model transsonic effects by a peak at mach 1 which decays the further we are away from it.
             ts_eff = _p * math.exp(-0.5* (dv / sigma)**2 ) / (sigma * math.sqrt(2*math.pi))
 
             # Log the values for the transsonic effect.
-            self._logger.write('ts_effects', ts_eff, domain=self._get_name())
-            self._logger.write('mach_no', self._dataset.get_mach_number(), domain='mach')
-            self._logger.write('speedofsound', self._dataset.get_speed_of_sound(), domain='mach')
+            self._log('ts_effects', ts_eff)
+            self._log('mach_no', self._dataset.get_mach_number())
+            self._log('speedofsound', self._dataset.get_speed_of_sound())
 
             x = x + ts_eff
 

spatz/sensors/sensor.py

@@ -9,17 +9,24 @@ from pandas import NA
 from spatz.transforms import *
 from spatz.logger import *
 from spatz.dataset import *
+from spatz.simulations.data_source import DataSource
 
 
 class Sensor:
-    def __init__(self, dataset: Dataset, logger: Logger, transforms: List[Transform] = [], min_value=-np.inf, max_value=np.inf):
+    def __init__(
+            self, 
+            dataset: DataSource, 
+            logger: Logger, 
+            transforms: List[Transform] = [], 
+            min_value=-np.inf, 
+            max_value=np.inf):
         self._dataset = dataset
         self._logger = logger
         self._transforms = transforms
         self._min_value = min_value
         self._max_value = max_value
 
-    def set_dataset(self, dataset: Dataset):
+    def set_dataset(self, dataset: DataSource):
         self._dataset = dataset
 
     def set_logger(self, logger: Logger):

spatz/sensors/temperature/__init__.py

@@ -1 +1 @@
-from temperature import TemperatureSensor
+from spatz.sensors.temperature.temperature import TemperatureSensor

spatz/sensors/temperature/ms5611.py

@@ -8,7 +8,7 @@ from spatz.transforms import Transform
 
 
 class MS5611Temperature(TemperatureSensor):
-    def __init__(self, dataset: Dataset, transforms: List[Transform] = ...):
+    def __init__(self, dataset: Dataset, transforms: List[Transform] = []):
         super().__init__(dataset, transforms)
 
         self.__noise = GaussianNoise(0, 0.5)

spatz/simulation.py

@@ -2,6 +2,8 @@ from typing import List
 from numpy.random import normal
 from tqdm import tqdm
 
+from spatz.simulations.advanceable import Advanceable
+from spatz.simulations.data_source import DataSource
 from spatz.dataset import Dataset
 from spatz.logger import Logger
 from spatz.sensors import Sensor
@@ -35,9 +37,11 @@ class UniformTimeSteps:
         return self.__dt + noise
 
 
-class Simulation:
+class Simulation(Advanceable):
     def __init__(self, time_steps=UniformTimeSteps(0.01)):
-        self.__dataset = None
+        super().__init__()
+
+        self.__data_source = None
         self.__logger = None
         self.__sensors: List[Sensor] = []
         self.__time_steps = time_steps
@@ -46,26 +50,25 @@ class Simulation:
         idx = 0
 
         # Clear all logs and reset the dataset to the first time step.
-        self.__dataset.reset()
+        self.__data_source.reset()
         self.__logger.reset()
 
         if verbose:
-            pbar = tqdm(total=self.__dataset.get_length())
+            pbar = tqdm(total=self.__data_source.get_length())
 
         while True:
-            t = self.__dataset.get_time()
+            t = self.get_time()
             dt = self.__time_steps(t)
             t_ = t + dt
             idx += 1
 
-            if t_ > self.__dataset.get_length():
+            if t_ > self.__data_source.get_length():
                 break
 
-            if until is not None and self.__dataset.get_phase() == until:
+            if until is not None and self.__data_source.get_phase() == until:
                 break
 
-            self.__dataset.step(dt)
-            self.__logger.step(dt)
+            self.advance(dt)
 
             if verbose:
                 pbar.update(dt)
@@ -75,31 +78,26 @@ class Simulation:
         if verbose:
             pbar.close()
 
-    def advance_to(self, t: float):
-        t_old = self.__dataset.get_time()
-        self.__dataset.step(t - t_old)
-        self.__logger.step(t - t_old)
+    def _on_step(self, dt: float):
+        self.__data_source.advance(dt)
+        self.__logger.advance(dt)
 
-    def advance(self, dt: float):
-        self.__dataset.step(dt)
-        self.__logger.step(dt)
-
-    def get_dataset(self) -> Dataset:
-        return self.__dataset
-    
-    def get_logger(self) -> Logger:
-        return self.__logger
-
-    def load(self, path: str):
-        self.__dataset = Dataset(path)
+    def load(self, source: DataSource):
+        self.__data_source = source
         self.__logger = Logger()
         
         for sensor in self.__sensors:
-            sensor.set_dataset(self.__dataset)
+            sensor.set_dataset(self.__data_source)
             sensor.set_logger(self.__logger)
 
         return self
 
+    def get_data_source(self) -> DataSource:
+        return self.__data_source
+    
+    def get_logger(self) -> Logger:
+        return self.__logger
+
     def add_sensor(self, sensor, *args, **kwargs) -> Sensor:
         """Register a new sensor for this simulation. A registered sensor can be called like a function and returns
         the current measurements. The class' constructor arguments have to be given aswell.
@@ -112,7 +110,7 @@ class Simulation:
         """
         assert issubclass(sensor, Sensor), "Expected a subclass of Sensor."
 
-        self.__sensors.append(sensor(self.__dataset, self.__logger, *args, **kwargs))
+        self.__sensors.append(sensor(self.__data_source, self.__logger, *args, **kwargs))
 
         return self.__sensors[-1]
 
@@ -132,10 +130,10 @@ class Simulation:
             attributes = observer_or_attributes
             assert len(attributes) != 0, "Observed attributes list must be nonempty."
 
-            self.__sensors.append(Observer(self.__dataset, self.__logger, attributes))
+            self.__sensors.append(Observer(self.__data_source, self.__logger, attributes))
         else:
             observer = observer_or_attributes
-            self.__sensors.append(observer(self.__dataset, self.__logger))
+            self.__sensors.append(observer(self.__data_source, self.__logger))
 
         return self.__sensors[-1]
 

spatz/simulations/advanceable.py

@@ -0,0 +1,47 @@
+from abc import abstractmethod
+
+
+class Advanceable:
+    def __init__(self) -> None:
+        self.reset()
+
+    def advance(self, dt: float):
+        """Advances the simulation data in time.
+
+        Args:
+            dt (float): The step in time to make.
+        """
+        self.__t += dt
+        self._on_step(dt)
+
+    def advance_to(self, t: float):
+        """Advances the simulation data to a new point in time.
+
+        Args:
+            t (float): The target point in time.
+        """
+        assert t > self.__t, 'Advanceable can only move forward in time.'
+
+        self.advance(t - self.__t)
+
+    def reset(self):
+        """
+        Reset the Avanceable object to its initial state.
+        """
+        self.__t = 0
+        self._on_reset()
+
+    @abstractmethod
+    def _on_step(self, dt: float):
+        pass
+
+    @abstractmethod
+    def _on_reset(self):
+        pass
+
+    def get_time(self) -> float:
+        """
+        Returns:
+            float: Returns the current time of the Advanceable.
+        """
+        return self.__t

spatz/simulations/csv_source.py

@@ -0,0 +1,91 @@
+import pandas as pd
+import numpy as np
+
+from typing import Literal, List
+from numpy.typing import NDArray
+
+from spatz.simulations.data_source import DataSource
+
+
+
+class CSVSource(DataSource):
+    def __init__(self, path: str, time_col: str, interpolation: Literal['linear']='linear') -> None:
+        """A data source that extracts all its data from a csv file.
+
+        Args:
+            time_col (str): The name of the column that contains time data.
+        """
+        super().__init__()
+
+        self._df = pd.read_csv(path)
+        self._time_col = time_col
+        self._idx = 0
+        self._interpolation = interpolation
+
+    def get_length(self) -> float:
+        return max(self._df[self._time_col])
+
+    def _on_reset(self):
+        pass
+
+    def _get_closest_idx(self, t: float) -> int:
+        """Gets an index _idx_ for the dataframe _df_ such that the values at the given time _t_ are somewhere between 
+        _idx_ and _idx+1_. 
+
+        Args:
+            t (float): The requested time.
+
+        Returns:
+            int: The computed index.
+        """
+        idx = (self._df[self._time_col] - t).abs().idxmin()
+        idx = idx if self._df[self._time_col].loc[idx] <= t else idx - 1
+
+        return idx
+
+    def _on_step(self, _: float):
+        self._idx = self._get_closest_idx(self.get_time())
+
+    def fetch_value(self, name: str, t: float | None = None, custom_interpolation=None) -> float:
+        """Get a specific value from the dataframe.
+
+        Args:
+            name (str): The name of the value to fetch.
+            t (float): Allows specification of a different time instead of the current time. None for current time.
+
+        Returns:
+            float: Returns the requested value.
+        """
+        idx = self._idx if t is None else self._get_closest_idx(t)
+
+        if self._interpolation == 'linear':
+            t_min = self._df.at[idx, self._time_col]
+            t_max = self._df.at[idx + 1, self._time_col]
+
+            # Sometimes no time passes in-between two samples.
+            if t_max == t_min:
+                return self._df.at[name, idx]
+            
+            # Compute the weight for interpolation.
+            alpha = (self.get_time() - t_min) / (t_max - t_min)
+
+            if custom_interpolation is not None:
+                a = self._df.at[idx, name]
+                b = self._df.at[idx + 1, name]
+
+                return custom_interpolation(a, b, alpha)
+
+            # Interpolate linearly between the two data points.
+            return (1 - alpha) * self._df.at[idx, name] + alpha * self._df.at[idx + 1, name]
+
+    def fetch_values(self, names: List[str], t: float | None = None, custom_interpolation=None) -> NDArray:
+        """Get specific values from the dataframe.
+
+        Args:
+            names (List[str]): Names of the values to get.
+            t (float): Allows specification of a different time instead of the current time. None for current time.
+
+        Returns:
+            np.array: Returns a numpy array containing the requested values in the same order as in the input list.
+        """
+        return np.asarray([self.fetch_value(name, t, custom_interpolation) for name in names])

spatz/simulations/data_source.py

@@ -0,0 +1,74 @@
+import numpy as np
+
+from spatz.simulations.advanceable import Advanceable
+
+from numpy.typing import NDArray
+from abc import abstractmethod
+from typing import Literal
+
+from ambiance import Atmosphere
+
+
+class DataSource(Advanceable):
+    def __init__(self) -> None:
+        super().__init__()
+
+    def get_speed_of_sound(self) -> float:
+        return Atmosphere(self.get_altitude()).speed_of_sound
+    
+    def get_mach_number(self) -> float:
+        speed = np.linalg.norm(self.get_velocity('global'))
+
+        return speed / self.get_speed_of_sound()
+
+    @abstractmethod
+    def get_length(self) -> float:
+        pass
+
+    @abstractmethod
+    def get_position(self) -> NDArray:
+        pass
+
+    @abstractmethod
+    def get_velocity(self, frame: Literal['global', 'local']) -> NDArray:
+        pass
+
+    @abstractmethod
+    def get_acceleration(self, frame: Literal['global', 'local']) -> NDArray:
+        pass
+
+    @abstractmethod
+    def get_attitude(self) -> NDArray:
+        pass
+
+    @abstractmethod
+    def local_to_global(self) -> NDArray:
+        pass
+
+    @abstractmethod
+    def global_to_local(self) -> NDArray:
+        pass
+
+    @abstractmethod
+    def get_angular_velocity(self) -> NDArray:
+        pass
+
+    @abstractmethod
+    def get_static_pressure(self) -> float:
+        pass
+
+    @abstractmethod
+    def get_temperature(self) -> float:
+        pass
+
+    @abstractmethod
+    def get_longitude(self) -> float:
+        pass
+
+    @abstractmethod
+    def get_latitude(self) -> float:
+        pass
+
+    @abstractmethod
+    def get_altitude(self) -> float:
+        pass

spatz/simulations/rocketpy.py

@@ -0,0 +1,87 @@
+import numpy as np
+
+from typing import Literal
+from numpy.typing import NDArray
+
+from spatz.simulations.csv_source import CSVSource
+
+
+class RocketPyCSV(CSVSource):
+    def __init__(self, path: str, interpolation: Literal['linear'] = 'linear') -> None:
+        super().__init__(path, ' Time (s)', interpolation)
+
+    def get_position(self) -> NDArray:
+        return self.fetch_values([' X (m)', ' Y (m)', ' Z (m)'])
+
+    def get_velocity(self, frame: Literal['global', 'local']) -> NDArray:
+        vel_global = self.fetch_values([' Vx (m/s)', ' Vy (m/s)', ' Vz (m/s)'])
+
+        if frame == 'global':
+            return vel_global
+        
+        return self.global_to_local() @ vel_global
+
+    def get_acceleration(self, frame: Literal['global', 'local']) -> NDArray:
+        acc_global = self.fetch_values([' Ax (m/s²)', ' Ay (m/s²)', ' Az (m/s²)'])
+
+        if frame == 'global':
+            return acc_global
+        
+        return self.global_to_local() @ acc_global
+
+    def get_attitude(self) -> NDArray:
+        t_min = self._df.at[self._idx, self._time_col]
+        t_max = self._df.at[self._idx + 1, self._time_col]
+
+        def slerp(a, b, alpha):
+            theta = np.arccos(np.clip(np.dot(a, b), -1, 1))
+
+            if np.isclose(theta, 0):
+                return a
+                
+            return (a * np.sin((1-alpha) * theta) + b * np.sin(alpha * theta)) / np.sin(theta)
+        
+        qa = np.array([self._df.at[self._idx, ' e0'], self._df.at[self._idx, ' e1'], self._df.at[self._idx, ' e2'], self._df.at[self._idx, ' e3']])
+        qb = np.array([self._df.at[self._idx+1, ' e0'], self._df.at[self._idx+1, ' e1'], self._df.at[self._idx+1, ' e2'], self._df.at[self._idx+1, ' e3']])
+
+        alpha = (self.get_time() - t_min) / (t_max - t_min)
+
+        return slerp(qa, qb, alpha)
+
+    def global_to_local(self) -> NDArray:
+        quat = self.get_attitude()
+
+        e0, e1, e2, e3 = quat[0], quat[1], quat[2], quat[3]
+
+        # Taken from:
+        # https://docs.rocketpy.org/en/latest/technical/equations_of_motion.html
+        mat = np.array([
+            [e0**2 + e1**2 - e2**2 - e3**2, 2*(e1*e2+e0*e3), 2*(e1*e3 - e0*e2)], 
+            [2*(e1*e2 - e0*e3), e0**2 - e1**2 + e2**2 - e3**2, 2*(e2*e3 + e0*e1)], 
+            [2*(e1*e3 + e0*e2), 2*(e2*e3 - e0*e1), e0**2 - e1**2 - e2**2 + e3**2]
+        ])
+        
+        return mat
+
+    def local_to_global(self) -> NDArray:
+        return self.global_to_local().T
+
+    def get_angular_velocity(self) -> NDArray:
+        return self.fetch_values([' ω1 (rad/s)',' ω2 (rad/s)',' ω3 (rad/s)'])
+
+    def get_static_pressure(self) -> float:
+        return self.fetch_value(' Pressure (Pa)')
+
+    def get_temperature(self) -> float:
+        raise NotImplementedError()
+
+    def get_longitude(self) -> float:
+        return self.fetch_value(' Longitude (°)')
+
+    def get_latitude(self) -> float:
+        return self.fetch_value(' Latitude (°)')
+
+    def get_altitude(self) -> float:
+        return self.fetch_value(' Z (m)')
+
+