Improve docstring quality and consistency

pyproject.toml

@@ -150,6 +150,7 @@ preview = true
 # https://docs.astral.sh/ruff/rules/
 select = [
     "B",
+    "D",
     "E",
     "F",
     "I",
@@ -162,6 +163,15 @@ select = [
 ignore = [
     "B008", # Function call in default argument
     "B024", # Abstract base class without abstract methods
+    "D100", # Missing docstring in public module
+    "D104", # Missing docstring in public package
+    "D105", # Missing docstring in magic method
+    "D200", # One-line docstring should fit on one line with quotes
+    "D202", # No blank lines allowed after function docstring
+    "D205", # 1 blank line required between summary line and description
+    "D212", # Multi-line docstring summary should start at the first line
+    "D411", # Missing blank line before section
+    "D413", # Missing blank line after last section
     "E402", # Module level import not at top of file
     "E501", # Line too long
     "E731", # Do not assign a `lambda` expression, use a `def`
@@ -173,9 +183,11 @@ ignore = [
 [tool.ruff.lint.per-file-ignores]
 # Ignore `E402` (import violations) in all `__init__.py` files
 "**/{tests,docs,tools}/*" = ["E402"]
-"**/{tests}/*" = ["B007"]
+"**/{tests,examples}/*" = ["B007", "D100", "D102", "D103"]
 "__init__.py" = ["F401"]
 "docs/conf.py" = ["F401"]
+"src/jaxsim/exceptions.py" = ["D401"]
+"src/jaxsim/logging.py" = ["D101", "D103"]
 
 # ==================
 # Pixi configuration

src/jaxsim/api/com.py

@@ -279,7 +279,7 @@ def other_representation_to_body(
         C_v̇_WL: jtp.Vector, C_v_WC: jtp.Vector, L_H_C: jtp.Matrix, L_v_LC: jtp.Vector
     ) -> jtp.Vector:
         """
-        Helper to convert the body-fixed representation of the link bias acceleration
+        Convert the body-fixed representation of the link bias acceleration
         C_v̇_WL expressed in a generic frame C to the body-fixed representation L_v̇_WL.
         """
 

src/jaxsim/api/common.py

@@ -26,7 +26,7 @@
 
 
 def named_scope(fn, name: str | None = None) -> Callable[_P, _R]:
-    """Applies a JAX named scope to a function for improved profiling and clarity."""
+    """Apply a JAX named scope to a function for improved profiling and clarity."""
 
     @functools.wraps(fn)
     def wrapper(*args: _P.args, **kwargs: _P.kwargs) -> _R:

src/jaxsim/api/contact.py

@@ -293,6 +293,9 @@ def in_contact(
 def estimate_good_soft_contacts_parameters(
     *args, **kwargs
 ) -> jaxsim.rbda.contacts.ContactParamsTypes:
+    """
+    Estimate good soft contacts parameters. Deprecated, use `estimate_good_contact_parameters` instead.
+    """
 
     msg = "This method is deprecated, please use `{}`."
     logging.warning(msg.format(estimate_good_contact_parameters.__name__))

src/jaxsim/api/data.py

@@ -456,7 +456,8 @@ def generalized_position(self) -> tuple[jtp.Matrix, jtp.Vector]:
     @jax.jit
     def generalized_velocity(self) -> jtp.Vector:
         r"""
-        Get the generalized velocity
+        Get the generalized velocity.
+
         :math:`\boldsymbol{\nu} = (\boldsymbol{v}_{W,B};\, \boldsymbol{\omega}_{W,B};\, \mathbf{s}) \in \mathbb{R}^{6+n}`
 
         Returns:

src/jaxsim/api/kin_dyn_parameters.py

@@ -52,10 +52,16 @@ class KinDynParameters(JaxsimDataclass):
 
     @property
     def parent_array(self) -> jtp.Vector:
+        r"""
+        Return the parent array :math:`\lambda(i)` of the model.
+        """
         return self._parent_array.get()
 
     @property
     def support_body_array_bool(self) -> jtp.Matrix:
+        r"""
+        Return the boolean support parent array :math:`\kappa_{b}(i)` of the model.
+        """
         return self._support_body_array_bool.get()
 
     @staticmethod
@@ -648,7 +654,16 @@ def build_from_inertial_parameters(
     def build_from_flat_parameters(
         index: jtp.IntLike, parameters: jtp.VectorLike
     ) -> LinkParameters:
+        """
+        Build a LinkParameters object from a flat vector of parameters.
+
+        Args:
+            index: The index of the link.
+            parameters: The flat vector of parameters.
 
+        Returns:
+            The LinkParameters object.
+        """
         index = jnp.array(index).squeeze().astype(int)
 
         m = jnp.array(parameters[0]).squeeze().astype(float)
@@ -772,7 +787,9 @@ class ContactParameters(JaxsimDataclass):
 
     @property
     def indices_of_enabled_collidable_points(self) -> npt.NDArray:
-
+        """
+        Return the indices of the enabled collidable points.
+        """
         return np.where(np.array(self.enabled))[0]
 
     @staticmethod

src/jaxsim/api/model.py

@@ -63,6 +63,9 @@ class JaxSimModel(JaxsimDataclass):
 
     @property
     def description(self) -> ModelDescription:
+        """
+        Return the model description.
+        """
         return self._description.get()
 
     def __eq__(self, other: JaxSimModel) -> bool:
@@ -1015,7 +1018,7 @@ def to_active(
         W_v̇_WB: jtp.Vector, W_H_C: jtp.Matrix, W_v_WB: jtp.Vector, W_v_WC: jtp.Vector
     ) -> jtp.Vector:
         """
-        Helper to convert the inertial-fixed apparent base acceleration W_v̇_WB to
+        Convert the inertial-fixed apparent base acceleration W_v̇_WB to
         another representation C_v̇_WB expressed in a generic frame C.
         """
 
@@ -1376,7 +1379,7 @@ def inverse_dynamics(
 
     def to_inertial(C_v̇_WB, W_H_C, C_v_WB, W_v_WC):
         """
-        Helper to convert the active representation of the base acceleration C_v̇_WB
+        Convert the active representation of the base acceleration C_v̇_WB
         expressed in a generic frame C to the inertial-fixed representation W_v̇_WB.
         """
 
@@ -1825,7 +1828,7 @@ def other_representation_to_inertial(
         C_v̇_WB: jtp.Vector, C_v_WB: jtp.Vector, W_H_C: jtp.Matrix, W_v_WC: jtp.Vector
     ) -> jtp.Vector:
         """
-        Helper to convert the active representation of the base acceleration C_v̇_WB
+        Convert the active representation of the base acceleration C_v̇_WB
         expressed in a generic frame C to the inertial-fixed representation W_v̇_WB.
         """
 
@@ -1961,7 +1964,7 @@ def body_to_other_representation(
         L_v̇_WL: jtp.Vector, L_v_WL: jtp.Vector, C_H_L: jtp.Matrix, L_v_CL: jtp.Vector
     ) -> jtp.Vector:
         """
-        Helper to convert the body-fixed apparent acceleration L_v̇_WL to
+        Convert the body-fixed apparent acceleration L_v̇_WL to
         another representation C_v̇_WL expressed in a generic frame C.
         """
 

src/jaxsim/api/ode.py

@@ -15,12 +15,32 @@
 
 
 class SystemDynamicsFromModelAndData(Protocol):
+    """
+    Protocol defining the signature of a function computing the system dynamics
+    given a model and data object.
+    """
+
     def __call__(
         self,
         model: js.model.JaxSimModel,
         data: js.data.JaxSimModelData,
         **kwargs: dict[str, Any],
-    ) -> tuple[ODEState, dict[str, Any]]: ...
+    ) -> tuple[ODEState, dict[str, Any]]:
+        """
+        Compute the system dynamics given a model and data object.
+
+        Args:
+            model: The model to consider.
+            data: The data of the considered model.
+            **kwargs: Additional keyword arguments.
+
+        Returns:
+            A tuple with an `ODEState` object storing in each of its attributes the
+            corresponding derivative, and the dictionary of auxiliary data returned
+            by the system dynamics evaluation.
+        """
+
+        pass
 
 
 def wrap_system_dynamics_for_integration(

src/jaxsim/exceptions.py

@@ -17,6 +17,8 @@ def raise_if(
         msg:
             The message to display when the exception is raised. The message can be a
             format string (fmt), whose fields are filled with the args and kwargs.
+        *args: The arguments to fill the format string.
+        **kwargs: The keyword arguments to fill the format string
     """
 
     # Disable host callback if running on unsupported hardware or if the user
@@ -61,12 +63,18 @@ def _run_callback_only_if_condition_is_true(*args, **kwargs) -> None:
 def raise_runtime_error_if(
     condition: bool | jax.Array, msg: str, *args, **kwargs
 ) -> None:
+    """
+    Raise a RuntimeError if a condition is met. Useful in jit-compiled functions.
+    """
 
     return raise_if(condition, RuntimeError, msg, *args, **kwargs)
 
 
 def raise_value_error_if(
     condition: bool | jax.Array, msg: str, *args, **kwargs
 ) -> None:
+    """
+    Raise a ValueError if a condition is met. Useful in jit-compiled functions.
+    """
 
     return raise_if(condition, ValueError, msg, *args, **kwargs)

src/jaxsim/integrators/common.py

@@ -36,9 +36,25 @@
 
 
 class SystemDynamics(Protocol[State, StateDerivative]):
+    """
+    Protocol defining the system dynamics.
+    """
+
     def __call__(
         self, x: State, t: Time, **kwargs
-    ) -> tuple[StateDerivative, dict[str, Any]]: ...
+    ) -> tuple[StateDerivative, dict[str, Any]]:
+        """
+        Compute the state derivative of the system.
+
+        Args:
+            x: The state of the system.
+            t: The time of the system.
+            **kwargs: Additional keyword arguments.
+
+        Returns:
+            The state derivative of the system and the auxiliary dictionary.
+        """
+        pass
 
 
 # =======================
@@ -48,6 +64,9 @@ def __call__(
 
 @jax_dataclasses.pytree_dataclass
 class Integrator(JaxsimDataclass, abc.ABC, Generic[State, StateDerivative]):
+    """
+    Factory class for integrators.
+    """
 
     dynamics: Static[SystemDynamics[State, StateDerivative]] = dataclasses.field(
         repr=False, hash=False, compare=False, kw_only=True
@@ -110,6 +129,9 @@ def step(
     def __call__(
         self, x0: State, t0: Time, dt: TimeStep, **kwargs
     ) -> tuple[NextState, dict[str, Any]]:
+        """
+        Perform a single integration step.
+        """
         pass
 
     def init(
@@ -121,6 +143,9 @@ def init(
         include_dynamics_aux_dict: bool = False,
         **kwargs,
     ) -> dict[str, Any]:
+        """
+        Initialize the integrator. This method is deprecated.
+        """
 
         logging.warning(
             "The 'init' method has been deprecated. There is no need to call it."
@@ -131,6 +156,18 @@ def init(
 
 @jax_dataclasses.pytree_dataclass
 class ExplicitRungeKutta(Integrator[PyTreeType, PyTreeType], Generic[PyTreeType]):
+    """
+    Base class for explicit Runge-Kutta integrators.
+
+    Attributes:
+        A: The Runge-Kutta matrix.
+        b: The weights coefficients.
+        c: The nodes coefficients.
+        order_of_bT_rows: The order of the solution.
+        row_index_of_solution: The row of the integration output corresponding to the final solution.
+        fsal_enabled_if_supported: Whether to enable the FSAL property, if supported.
+        index_of_fsal: The index of the intermediate derivative to be used as the first derivative of the next iteration.
+    """
 
     # The Runge-Kutta matrix.
     A: ClassVar[jtp.Matrix]
@@ -156,10 +193,16 @@ class ExplicitRungeKutta(Integrator[PyTreeType, PyTreeType], Generic[PyTreeType]
 
     @property
     def has_fsal(self) -> bool:
+        """
+        Check if the integrator supports the FSAL property.
+        """
         return self.fsal_enabled_if_supported and self.index_of_fsal is not None
 
     @property
     def order(self) -> int:
+        """
+        Return the order of the integrator.
+        """
         return self.order_of_bT_rows[self.row_index_of_solution]
 
     @override
@@ -221,6 +264,9 @@ def build(
     def __call__(
         self, x0: State, t0: Time, dt: TimeStep, **kwargs
     ) -> tuple[NextState, dict[str, Any]]:
+        """
+        Perform a single integration step.
+        """
 
         # Here z is a batched state with as many batch elements as b.T rows.
         # Note that z has multiple batches only if b.T has more than one row,
@@ -331,7 +377,9 @@ def get_ẋ0_and_aux_dict() -> tuple[StateDerivative, dict[str, Any]]:
         def scan_body(
             carry: jax.Array, i: int | jax.Array
         ) -> tuple[jax.Array, dict[str, Any]]:
-            """"""
+            """
+            Compute the kᵢ derivative of the Runge-Kutta stage.
+            """
 
             # Unpack the carry, i.e. the stacked kᵢ vectors.
             K = carry
@@ -498,6 +546,16 @@ class ExplicitRungeKuttaSO3Mixin:
     def post_process_state(
         cls, x0: js.ode_data.ODEState, t0: Time, xf: js.ode_data.ODEState, dt: TimeStep
     ) -> js.ode_data.ODEState:
+        r"""
+        Post-process the integrated state at :math:`t_f = t_0 + \Delta t` so that the
+        quaternion is normalized.
+
+        Args:
+            x0: The initial state of the system.
+            t0: The initial time of the system.
+            xf: The final state of the system obtain through the integration.
+            dt: The time step used for the integration.
+        """
 
         # Extract the initial base quaternion.
         W_Q_B_t0 = x0.physics_model.base_quaternion