Sample Models

The SDEverywhere repository has a models directory that contains many sample Vensim models. These models can be used to exercise the SDEverywhere transpiler and to verify that it produces results that are functionally equivalent to what Vensim produces.

Refer to the Supported Vensim Functions page for the full list of Vensim functions that are currently supported in SDEverywhere.

Running the tests

There is a test runner script in tests/modeltests. For each model in the models directory, it:

• uses sde to generate a C version of the model
• compiles the C model to a native executable
• runs the native executable
• compares the model outputs to the dat file produced by Vensim

To run the entire integration test suite:

cd SDEverywhere
pnpm test:c-int

To test a single model:

cd SDEverywhere
pnpm test:c-int {modelname}

located in the models directory in a folder with the base name of the .mdl file. The C code will be written with the same base name in the build directory.

List of sample models

The following models are included as samples and test cases for various Vensim features.

Model	Description
active_initial	ACTIVE INITIAL function
allocate	ALLOCATE AVAILABLE function
allocate_ptype	priority curve types for allocation functions
arrays_cname	1-D and 2-D arrays with a variety of subscript references using C language var names
arrays_varname	1-D and 2-D arrays with a variety of subscript references using Vensim var names
comments	Range, units, and documentation removal
delay	DELAY and DELAY3 functions
delayfixed	DELAY FIXED function
delayfixed2	DELAY FIXED function
directconst	GET DIRECT CONSTANTS function
directdata	GET DIRECT DATA function
directlookups	GET DIRECT LOOKUPS function
directsubs	GET DIRECT SUBSCRIPT function
elmcount	ELMCOUNT function
except	Exception equations
except2	Exception equations
extdata	Loading external data from DAT files
getdata	GET DATA BETWEEN TIMES function
index	Apply-to-all and non-apply-to-all arrays
initial	INITIAL function
interleaved	Demonstrating a case where non-apply-to-all array elements are separated in eval order
lookup	Lookup variables and functions
mapping	Mapping subranges
multimap	Mapping a subscript range to multiple ranges
npv	NPV function
preprocess	SDEverywhere preprocessor phase
prune	Removing variables that are not referenced by input or output variables
pulsetrain	PULSE TRAIN function
quantum	QUANTUM function
ref	An eval order that require an apply-to-all array to become non-apply-to-all
sample	SAMPLE function
sir	SIR infection model
smooth	SMOOTH function
smooth3	SMOOTH3 function
specialchars	Variables with special characters allowed by Vensim
subalias	Subscript range aliasing with <->
subscript	Subscript references in various orders
sum	SUM expressions
sumif	Handling nested subscripts within array function calls
trend	TREND function
vector	Vector functions

Directory structure

Each model directory contains some or all of the following files:

Filename	Description
{model}.mdl	Vensim model
{model}.dat	Data file exported in DAT text format
{model}.txt	SDEverywhere log file in DAT format with values for all time steps
{model}_spec.json	Model specification including input and output variables of interest
{model}_vars.txt	SDEverywhere variable analysis
{model}_check.sh	Optional script that runs additional checks on the generated C code