rxSolveAdjointRk4: Solve a model with an in-engine discrete-adjoint ('s') method

In rxode2: Facilities for Simulating from ODE-Based Models

Solve a model with an in-engine discrete-adjoint (s) method

Description

Applies the (cached) adjoint expansion, solves with the requested adjoint method, and drops the internal ⁠rx__adj*⁠ lhs, returning the full-trajectory ⁠rx__sens_<state>_BY_<param>__⁠ columns. The stiff analytic Jacobian is emitted into the expansion automatically, inferred from method.

Usage

rxSolveAdjointRk4(
  object,
  events,
  params = NULL,
  calcSens,
  method = "rk4s",
  ...
)

Arguments

object	model definition accepted by rxode2().
events	an rxode2 event table / data set.
params	optional named parameter vector or data frame (per subject).
calcSens	character vector of parameters to differentiate w.r.t.
method	adjoint solve method (default "rk4s"). May be a composite ("dop853s+ros4s").
...	passed to rxSolve().

Value

the solved data frame with ⁠rx__sens_<state>_BY_<param>__⁠ columns.

Author(s)

Matthew L. Fidler

rxode2 documentation built on July 28, 2026, 5:08 p.m.