Model File Reference

FeRx models are defined in .ferx files using a declarative DSL. Each file is organized into blocks, each denoted by a [block_name] header.

Block Overview

BlockRequiredPurpose
[parameters]YesDefine theta, omega, and sigma parameters
[individual_parameters]YesMap population parameters to individual PK parameters
[structural_model]YesSpecify the PK model (analytical or ODE)
[error_model]YesDefine the residual error model
[odes]If ODEODE right-hand-side equations
[fit_options]NoConfigure estimation method and optimizer
[simulation]NoDefine a simulation trial design

Minimal Example

[parameters]
  theta TVCL(0.1, 0.001, 10.0)
  theta TVV(10.0, 0.1, 500.0)
  omega ETA_CL ~ 0.09
  omega ETA_V  ~ 0.04
  sigma ADD_ERR ~ 1.0

[individual_parameters]
  CL = TVCL * exp(ETA_CL)
  V  = TVV  * exp(ETA_V)

[structural_model]
  pk one_cpt_iv_bolus(cl=CL, v=V)

[error_model]
  DV ~ additive(ADD_ERR)

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