dot-rxAdjointSolve: Solve the full-trajectory adjoint sensitivities for a model

In rxode2: Facilities for Simulating from ODE-Based Models

Solve the full-trajectory adjoint sensitivities for a model

Description

Reconstructs dy_k(t_i)/dp for every output state k, parameter p and output time t_i via backward (adjoint) integration, returning the same ⁠rx__sens_<state>_BY_<param>__⁠ columns that forward sensitivities produce.

Usage

.rxAdjointSolve(
  object,
  params,
  events,
  calcSens,
  outTimes,
  adjStates = NULL,
  denseBy = 0.01,
  atol = 1e-10,
  rtol = 1e-10
)

Arguments

object	model definition accepted by rxode2() (text, rxode2 object, or function/ui).
params	named numeric vector of parameter values.
events	event table / data used to define dosing.
calcSens	character vector of parameter names to differentiate with respect to.
outTimes	numeric vector of output (observation) times at which the sensitivities are requested.
adjStates	character vector of output states of interest. Defaults to all ODE states (full forward-sensitivity parity).
denseBy	grid spacing for the forward checkpoint trajectory; smaller values reduce the covariate-interpolation error.
atol, rtol	solver tolerances used for both the forward checkpoint and the backward sweeps.

Value

data.frame with a time column and one ⁠rx__sens_<state>_BY_<param>__⁠ column per (state, param) pair.

Author(s)

Matthew L. Fidler

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