r2ogs6: An R wrapper of the OpenGeoSys 6 Multiphysics Simulator

Our package r2ogs6 provides a file-based interface of the multi-physics simulation code OpenGeoSys 6 (Bilke et al., 2019; Kolditz et al., 2012) to the R programing and statistical computing environment.r2ogs6 enables R users to perform and analyze simulation models of the sub-surface earth system in R. It allows to access the capabilities of OpenGeoSys 6 to simulate thermo-hydro-mechanical-chemical and biological (THMC/B) processes in porous and fractured media within R. In this way, r2ogs6 enables R users to model sub-surface phenomena and technologies such as groundwater flow, reactive transport, geothermal energy usage and/or nuclear waste repositories as well as to analyze and further process simulation output.r2ogs6 enables users to prepare and manipulate OpenGeoSys 6 simulation models, run the simulations and retrieve corresponding output, all within an R session or simple R scripts.Therefore, R classes and functions were designed to communicate with the respective OpenGeoSys 6 input and output files as well as executables.In addition to single-simulation runs, r2ogs6 supports ensemble runs that can be used to set up uncertainty and sensitivity analyses as well as parameter studies.Furthermore, r2ogs6 allows conducting and documenting OpenGeoSys 6 simulations in reproducible R scripts or notebooks.As OpenGeoSys 6 is continuously being developed further, code generation functions for r2ogs6 developers were included to speed up the package updating process in case of future changes to OpenGeoSys 6. r2ogs6 was designed to be used by domain researchers, data scientists and students working with OpenGeoSys 6.Moreover, r2ogs6 was intended to include OpenGeoSys 6 into R based scientific workflows and aims to bridge the gap between data produced by a scientific simulation code and data science.