The Generalized Algorithm for Nutrient, Growth, Stoichiometric and Thermodynamic Analysis (GANGSTA; https://github.com/FluvialLandscapeLab/gangsta) is a software framework that automates the instantiation of formalized, user-defined conceptual models of biogeochemical systems as code necessary to execute constraint-based simulation models of conceptualized systems.
The gangstaBuiltPackage contains an installable R package for creating GANGSTA-derived models. Customary function documentation and a vignette describing how to instantiate and execute user-defined GANGSTA-derived simulation models are included in the software.
Place the gangsta folder into the folder where R libraries are stored; e.g., C:\Users\YourPCName\Documents\R\win-library\3.5. Open R. Load the gangsta package in R with the function library(gangsta). Access the vignette and help files with ??gangsta.