debugger: Debug stock-and-flow model

In sdbuildR: Easily Build, Simulate, and Visualise Stock-and-Flow Models

Debug stock-and-flow model

Description

Check for common formulation problems in a stock-and-flow model.

Usage

debugger(sfm, quietly = FALSE)

Arguments

sfm	Stock-and-flow model, object of class sdbuildR_xmile.
quietly	If TRUE, don't print problems. Defaults to FALSE.

Details

The following problems are detected:

• An absence of stocks

• Flows without a source (from) or target (to)

• Flows connected to a stock that does not exist

• Undefined variable references in equations

• Circularity in equations

• Connected stocks and flows without both having units or no units

• Missing unit definitions

The following potential problems are detected:

• Absence of flows

• Stocks without inflows or outflows

• Equations with a value of 0

Value

If quietly = FALSE, list with problems and potential problems.

Examples

# No issues
sfm <- xmile("SIR")
debugger(sfm)

# Detect absence of stocks or flows
sfm <- xmile()
debugger(sfm)

# Detect stocks without inflows or outflows
sfm <- xmile() |> build("Prey", "stock")
debugger(sfm)

# Detect circularity in equation definitions
sfm <- xmile() |>
  build("Prey", "stock", eqn = "Predator") |>
  build("Predator", "stock", eqn = "Prey")
debugger(sfm)

sdbuildR documentation built on Nov. 19, 2025, 5:07 p.m.