Introduction

This package provides methods to interact with the modelling framework Simplace¹. Simplace is written in Java (and some parts in Scala) so one can access it from R via rJava. The purpose of this package is to simplify the interaction between R and Simplace, by providing functions to:

• initialize and configure Simplace
• load a simulation (solution and project)
• parameterize the simulation
• run whole simulation or run it stepwise
• get simulation output and convert it to formats suitable for R

Installing the Simplace Framework

For installing Simplace, please consult the webpage www.simplace.net. A brief guide to install Simplace:

• If you don’t have installed Java, please install an appropriate version of the (JRE or JDK) from openjdk.org or adoptium.net (recommended).
• Get Simplace from www.simplace.net
• Install the simplace package in R:

install.packages('simplace')

Basic Usage

The usage of Simplace in R follows roughly this scheme:

• init Simplace by providing the path to your simplace installation directory, your working directory and your outputs
• open a Simplace project form a solution (and project) file
• create a list of simulation parameters you want to change
• create and run a Simulation
• get the result from the simulation
• convert the result to a R object (data.frame, list etc.)

Troubleshooting

• Package rJava should be installed automatically with simplace. If not, install it manually:
  install.packages('rJava')
• Architecture of R and Java have to match. If you are using 64-bit Java, you have to use 64-bit R.
• If you want to use the development version instead of the console mode, make sure that the projects simplace_core, simplace_modules and optionally simplace_run are in a common directory and set the installation dir to this directory.

Example

library(simplace)
SimplaceInstallationDir <- findFirstSimplaceInstallation()

Solution <- paste(SimplaceInstallationDir,
        "simplace_run/simulation/gk/solution/complete/Complete.sol.xml",sep="")

simplace <- initSimplace(SimplaceInstallationDir)

openProject(simplace, Solution)

parameter <- list()
parameter$enddate <- "31-12-1992"

sid <- createSimulation(simplace,parameter)
runSimulations(simplace)

result <- getResult(simplace,"DIAGRAM_OUT", sid);

closeProject(simplace)

simdata <- resultToDataframe(result)

dates <- 300:730
weights <- simdata[dates,
    c("TOP_LINE_Roots","TOP_LINE_Leaves","TOP_LINE_Stems","TOP_LINE_StorageOrgans")]
matplot(dates,weights,type="l",xlab="Days",ylab="Weight [g/m2]",main="Simulated Biomass")
legend(300,800,legend=c("Roots","Leaves","Stems","Storage Organs"),lty=1:4,col=1:4)

resultlistexp <- resultToList(result,expand=TRUE)
water <- resultlistexp$BOTTOM_ARRAY_VolumetricWaterContent
wmat <- do.call(rbind,water)
wmatpart <- wmat[dates,]
layers <- dim(wmatpart)[2]
filled.contour(dates,-(layers:1),wmatpart[,layers:1],
               xlab="Day", ylab="Layer", main="Water content in soil",
               color.palette = function(n){rgb((n:1)/n,(n:1)/n,1)})