ProblemUpdater(par_getter, par_setter)

Encapsulates updating an AbstractODEProblem based on the problem itself by Callable (pu::ProblemUpdater)(prob).

Must be initialized with a callable AbstractProblemParGetter, e.g. KeysProblemParGetter and on a AbstractODEProblemParSetter, e.g. ODEProblemParSetter.

There are special functions to construct ProblemUpdater based on a given Problem:

• get_ode_problemupdater

get_ode_problemupdater(par_getter::AbstractProblemParGetter, u0, p)
get_ode_problemupdater(par_getter::AbstractProblemParGetter, sys::AbstractODESystem)

Construct a ProblemUpdater based on an constructed ODEProblemParSetterConcrete.

get_ode_problemupdater(par_getter::AbstractProblemParGetter, u0, p)
get_ode_problemupdater(par_getter::AbstractProblemParGetter, sys::AbstractODESystem)

Construct a ProblemUpdater based on an constructed ODEProblemParSetterConcrete.

AbstractProblemUpdater that returns the original AbstractODEProblem.

Supertype for callables that implement (::AbstractProblemParGetter)(problem) -> updated_problem

Concrete subtypes should implement function keys, so that an appropriate AbstractODEProblemParSetter can be constructed for ProblemUpdater.

KeysProblemParGetter(mapping::NTuple{N,Pair{Symbol, Symbol}, keys_state)

Provices callable (pg::KeysProblemParGetter)(pu::ProblemUpdater, prob), keys_state]. To be used to get the parameters/state vector to be set by ProblemUpdater.

Initialize with an mapping of NTuples of symbols (source -> target) that index into either get_state_labeled(pu.pset, prob) or get_par_labeled(pu.pset, prob)). Argument keys_state is a Tuple or Vector that iterates the Symbols in the state of an ODEProblem. It is required to know from which part of the problem to extract.

During an optimization, one does not want to recreate the problem from a symbolic system, but only update the problem. This can be difficult, because the parameters to update may be spread across initial state and other parameters. Further, the order of parameters after simplifying a system is not fixed.

A AbstractProblemUpdater helps with

• remake: translate the set of parameters -> an updated problem
• get_paropt: problem -> extract/approximate subset of parameters to optimize

The structure of optimized parameter Vector is described by an Axis object of ComponentArrays.jl. And several functions are defined to work with it. Specifically, the ComponentVector it employs a classification (classes_paropt), ,e.g. :state and :par for ODEProblems, below which, ComponentVectors of actual parameters are listed (keys_paropt](@ref)). Further functions extract information about the ComponentVector: axis_paropt, , count_paropt, symbols_paropt or attach information to a plain vector for convenient access or display: label_paropt, name_paropt.

remake(prob::AbstractSciMLProblem, popt, ps::AbstractProblemParSetter)

Return an updated problem given the parameters. Subtypes need to implement method remake_pset(prob, popt, pset)

get_paropt(pset::AbstractProblemParSetter, prob::SciMLBase.AbstractSciMLProblem; kwargs...)
get_paropt_labeled(pset::AbstractProblemParSetter, prob::SciMLBase.AbstractSciMLProblem; kwargs...)

Extract optimized parameters from the Problem. The labeled versions additionally calls label_paropt on the return value.

axis_paropt(pset::AbstractProblemParSetter)
axis_paropt_scalar(pset::AbstractProblemParSetter)
axis_paropt_flat1(pset::AbstractProblemParSetter)

Report the Axis of a CompoenentVector of parameters. The second version has a scalarized entry for state for each subvector of state. The third version provides an axis corresponding to flatten1(paropt).

function classes_paropt(pset::AbstractProblemParSetter)

Get the classes (as NTuple{Symbol}) which the AbstractProblemParSetter supports and requires in paropt.

count_paropt(::AbstractProblemParSetter)

Report length of the optimized parameters vector. This generally is different from the length of keys, because each key can describe a array.

keys_paropt(::AbstractProblemParSetter)

Report the keys of paropt below the classification level.

symbols_paropt(pset::AbstractProblemParSetter)

Report the names, i.e. symbols of optimized parameters respectively, i.e. the concatenation of components. Similar to ComponentArrays.label, but inferred from Axis object. Returns a Vector of length count_paropt

label_paropt(pset::AbstractProblemParSetter, popt::AbstractVector) 
label_paropt_flat1(pset::AbstractProblemParSetter, popt::AbstractVector)

Produce a labeled version, i.e. a ComponentVector of optimized parameters. The second version omits the highest level of labels, e.g. state and par in ODEProblemParSetter.

name_paropt(pset, popt::AbstractVector) 
name_paropt(pset, prob::AbstractSciMLProblem)

Produce a NamedVector of given state optimized parameters vector. Similar to label_paropt, but may print nicer. The second form calls get_paropt on the Problem.