Debug stock-and-flow model

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.

Value

Logical value indicating whether any problems were detected.

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

See also

Other build: as.data.frame.sdbuildR_sim(), as.data.frame.sdbuildR_xmile(), build(), find_dependencies(), get_build_code(), header(), macro(), plot.sdbuildR_xmile(), print.summary.sdbuildR_xmile(), summary.sdbuildR_xmile(), xmile()

Examples

# No issues
sfm <- xmile("SIR")
debugger(sfm)
#> No problems detected!
#> Potentially problematic:
#> * These variables have an equation of 0:
#> - Recovered

# Detect absence of stocks or flows
sfm <- xmile()
debugger(sfm)
#> Problems:
#> * Your model has no stocks.
#> 
#> Potentially problematic:
#> * Your model has no flows.

# Detect stocks without inflows or outflows
sfm <- xmile() |> build("Prey", "stock")
debugger(sfm)
#> No problems detected!
#> Potentially problematic:
#> * Your model has no flows.
#> 
#> * These variables have an equation of 0:
#> - Prey

# Detect circularity in equation definitions
sfm <- xmile() |>
  build("Prey", "stock", eqn = "Predator") |>
  build("Predator", "stock", eqn = "Prey")
debugger(sfm)
#> Problems:
#> * Ordering static equations failed. Circular dependencies detected involving variables: Predator, Prey
#> - Predator depends on Prey
#> - Prey depends on Predator
#> 
#> Potentially problematic:
#> * Your model has no flows.