Add documentation for undocumented SciMLBase API components

src/clock.jl

@@ -47,30 +47,60 @@ discrete-time systems that assume a fixed sample time, such as PID controllers a
 filters.
 """ SolverStepClock
 
+"""
+    isclock(clock)
+
+Returns `true` if the object is a valid clock type (specifically a `PeriodicClock`).
+This function is used for type checking in clock-dependent logic.
+"""
 isclock(c::Clocks.Type) = @match c begin
     PeriodicClock() => true
     _ => false
 end
 isclock(::TimeDomain) = false
 
+"""
+    issolverstepclock(clock)
+
+Returns `true` if the clock is a `SolverStepClock` that triggers at every solver step.
+This is useful for monitoring solver progress or implementing step-dependent logic.
+"""
 issolverstepclock(c::Clocks.Type) = @match c begin
     SolverStepClock() => true
     _ => false
 end
 issolverstepclock(::TimeDomain) = false
 
+"""
+    iscontinuous(clock)
+
+Returns `true` if the clock operates in continuous time (i.e., is a `ContinuousClock`).
+Continuous clocks allow events to occur at any real-valued time instant.
+"""
 iscontinuous(c::Clocks.Type) = @match c begin
     ContinuousClock() => true
     _ => false
 end
 iscontinuous(::TimeDomain) = false
 
+"""
+    iseventclock(clock)
+
+Returns `true` if the clock is an `EventClock` that triggers based on specific events.
+Event clocks are used for condition-based triggering in hybrid systems.
+"""
 iseventclock(c::Clocks.Type) = @match c begin
     EventClock() => true
     _ => false
 end
 iseventclock(::TimeDomain) = false
 
+"""
+    is_discrete_time_domain(clock)
+
+Returns `true` if the clock operates in discrete time (i.e., is not a continuous clock).
+Discrete time domains have specific sampling intervals or event-based triggering.
+"""
 is_discrete_time_domain(c::TimeDomain) = !iscontinuous(c)
 
 # workaround for https://github.com/Roger-luo/Moshi.jl/issues/43

src/function_wrappers.jl

@@ -1,5 +1,35 @@
+"""
+    AbstractWrappedFunction{iip}
+
+Abstract base type for function wrappers used in automatic differentiation and sensitivity analysis.
+These wrappers provide specialized interfaces for computing derivatives with respect to different variables.
+
+# Type Parameter
+- `iip`: Boolean indicating if the function is in-place (`true`) or out-of-place (`false`)
+"""
 abstract type AbstractWrappedFunction{iip} end
 isinplace(f::AbstractWrappedFunction{iip}) where {iip} = iip
+
+"""
+    TimeGradientWrapper{iip, fType, uType, P} <: AbstractWrappedFunction{iip}
+
+Wraps functions to compute gradients with respect to time. This wrapper is particularly useful for 
+sensitivity analysis and optimization problems where the time dependence of the solution is critical.
+
+# Fields
+- `f`: The function to wrap
+- `uprev`: Previous state value
+- `p`: Parameters
+
+# Type Parameters
+- `iip`: Boolean indicating if the function is in-place (`true`) or out-of-place (`false`)
+- `fType`: Type of the wrapped function
+- `uType`: Type of the state variables
+- `P`: Type of the parameters
+
+This wrapper enables automatic differentiation with respect to time by providing a consistent
+interface for computing `∂f/∂t` across different AD systems.
+"""
 mutable struct TimeGradientWrapper{iip, fType, uType, P} <: AbstractWrappedFunction{iip}
     f::fType
     uprev::uType
@@ -20,6 +50,27 @@ end
 
 (ff::TimeGradientWrapper{false})(t) = ff.f(ff.uprev, ff.p, t)
 
+"""
+    UJacobianWrapper{iip, fType, tType, P} <: AbstractWrappedFunction{iip}
+
+Wraps functions to compute Jacobians with respect to state variables `u`. This is one of the most 
+commonly used wrappers in the SciML ecosystem for computing the derivative of the right-hand side 
+function with respect to the state variables.
+
+# Fields
+- `f`: The function to wrap
+- `t`: Time value
+- `p`: Parameters
+
+# Type Parameters
+- `iip`: Boolean indicating if the function is in-place (`true`) or out-of-place (`false`)
+- `fType`: Type of the wrapped function
+- `tType`: Type of the time variable
+- `P`: Type of the parameters
+
+This wrapper enables efficient computation of `∂f/∂u` for Jacobian calculations in numerical solvers
+and automatic differentiation systems.
+"""
 mutable struct UJacobianWrapper{iip, fType, tType, P} <: AbstractWrappedFunction{iip}
     f::fType
     t::tType
@@ -43,6 +94,26 @@ end
 (ff::UJacobianWrapper{false})(uprev) = ff.f(uprev, ff.p, ff.t)
 (ff::UJacobianWrapper{false})(uprev, p, t) = ff.f(uprev, p, t)
 
+"""
+    TimeDerivativeWrapper{iip, F, uType, P} <: AbstractWrappedFunction{iip}
+
+Wraps functions to compute derivatives with respect to time. This wrapper is used when you need to 
+compute `∂f/∂t` for sensitivity analysis or when the function has explicit time dependence.
+
+# Fields
+- `f`: The function to wrap
+- `u`: State variables
+- `p`: Parameters
+
+# Type Parameters
+- `iip`: Boolean indicating if the function is in-place (`true`) or out-of-place (`false`)
+- `F`: Type of the wrapped function
+- `uType`: Type of the state variables
+- `P`: Type of the parameters
+
+This wrapper provides a consistent interface for time derivative computations across different
+automatic differentiation backends.
+"""
 mutable struct TimeDerivativeWrapper{iip, F, uType, P} <: AbstractWrappedFunction{iip}
     f::F
     u::uType
@@ -60,6 +131,26 @@ end
 (ff::TimeDerivativeWrapper{true})(du1, t) = ff.f(du1, ff.u, ff.p, t)
 (ff::TimeDerivativeWrapper{true})(t) = (du1 = similar(ff.u); ff.f(du1, ff.u, ff.p, t); du1)
 
+"""
+    UDerivativeWrapper{iip, F, tType, P} <: AbstractWrappedFunction{iip}
+
+Wraps functions to compute derivatives with respect to state variables. This wrapper is used for 
+computing `∂f/∂u` and is fundamental for Jacobian computations in numerical solvers.
+
+# Fields
+- `f`: The function to wrap
+- `t`: Time value
+- `p`: Parameters
+
+# Type Parameters
+- `iip`: Boolean indicating if the function is in-place (`true`) or out-of-place (`false`)
+- `F`: Type of the wrapped function
+- `tType`: Type of the time variable
+- `P`: Type of the parameters
+
+This wrapper enables efficient state derivative computations for use in automatic differentiation
+and numerical analysis algorithms.
+"""
 mutable struct UDerivativeWrapper{iip, F, tType, P} <: AbstractWrappedFunction{iip}
     f::F
     t::tType
@@ -75,6 +166,26 @@ UDerivativeWrapper(f::F, t, p) where {F} = UDerivativeWrapper{isinplace(f, 4)}(f
 (ff::UDerivativeWrapper{true})(du1, u) = ff.f(du1, u, ff.p, ff.t)
 (ff::UDerivativeWrapper{true})(u) = (du1 = similar(u); ff.f(du1, u, ff.p, ff.t); du1)
 
+"""
+    ParamJacobianWrapper{iip, fType, tType, uType} <: AbstractWrappedFunction{iip}
+
+Wraps functions to compute Jacobians with respect to parameters `p`. This wrapper is essential for 
+parameter estimation, inverse problems, and sensitivity analysis with respect to model parameters.
+
+# Fields
+- `f`: The function to wrap
+- `t`: Time value
+- `u`: State variables
+
+# Type Parameters
+- `iip`: Boolean indicating if the function is in-place (`true`) or out-of-place (`false`)
+- `fType`: Type of the wrapped function
+- `tType`: Type of the time variable
+- `uType`: Type of the state variables
+
+This wrapper enables efficient computation of `∂f/∂p` for parameter sensitivity analysis and
+optimization algorithms.
+"""
 mutable struct ParamJacobianWrapper{iip, fType, tType, uType} <: AbstractWrappedFunction{iip}
     f::fType
     t::tType
@@ -97,6 +208,24 @@ function (ff::ParamJacobianWrapper{false})(du1, p)
     du1 .= ff.f(ff.u, p, ff.t)
 end
 
+"""
+    JacobianWrapper{iip, fType, pType} <: AbstractWrappedFunction{iip}
+
+A general-purpose Jacobian wrapper that can be configured for different types of Jacobian computations. 
+This wrapper provides a unified interface for various Jacobian calculations across the SciML ecosystem.
+
+# Fields
+- `f`: The function to wrap
+- `p`: Parameters
+
+# Type Parameters
+- `iip`: Boolean indicating if the function is in-place (`true`) or out-of-place (`false`)
+- `fType`: Type of the wrapped function
+- `pType`: Type of the parameters
+
+This wrapper provides a flexible interface for Jacobian computations that can adapt to different
+automatic differentiation backends and numerical methods.
+"""
 mutable struct JacobianWrapper{iip, fType, pType} <: AbstractWrappedFunction{iip}
     f::fType
     p::pType

src/integrator_interface.jl

@@ -50,16 +50,50 @@ The length of the tuple is dependent on the method.
 function get_tmp_cache(i::DEIntegrator)
     error("get_tmp_cache!: method has not been implemented for the integrator")
 end
+"""
+    user_cache(integrator::DEIntegrator)
+
+Returns user-accessible cache components from the integrator. These are cache arrays that users
+can safely access and modify without breaking the internal integrator state.
+"""
 function user_cache(i::DEIntegrator)
     error("user_cache: method has not been implemented for the integrator")
 end
+
+"""
+    u_cache(integrator::DEIntegrator)
+
+Returns the state variable cache arrays used by the integrator. These contain intermediate
+state values during the integration process.
+"""
 function u_cache(i::DEIntegrator)
     error("u_cache: method has not been implemented for the integrator")
 end
+
+"""
+    du_cache(integrator::DEIntegrator)
+
+Returns the derivative cache arrays used by the integrator. These contain intermediate
+derivative values during the integration process.
+"""
 function du_cache(i::DEIntegrator)
     error("du_cache: method has not been implemented for the integrator")
 end
+
+"""
+    ratenoise_cache(integrator::DEIntegrator)
+
+Returns cache arrays for rate noise in stochastic differential equations. 
+Returns an empty tuple by default for deterministic problems.
+"""
 ratenoise_cache(i::DEIntegrator) = ()
+
+"""
+    rand_cache(integrator::DEIntegrator)
+
+Returns cache arrays for random number generation in stochastic differential equations.
+Returns an empty tuple by default for deterministic problems.
+"""
 rand_cache(i::DEIntegrator) = ()
 
 """