GeneralNlModel: Use this function to create objects of class NlModel.

In SoilR: Models of Soil Organic Matter Decomposition

Use this function to create objects of class NlModel.

Description

The function creates a numerical model for n arbitrarily connected pools. It is one of the constructors of class NlModel. It is used by some more specialized wrapper functions, but can also be used directly.

Usage

GeneralNlModel(
  t,
  TO,
  ivList,
  inputFluxes,
  solverfunc = deSolve.lsoda.wrapper,
  pass = FALSE
)

Arguments

t	A vector containing the points in time where the solution is sought.
TO	A object describing the model decay rates for the n pools, connection and feedback coefficients. The number of pools n must be consistent with the number of initial values and input fluxes.
ivList	A numeric vector containing the initial amount of carbon for the n pools. The length of this vector is equal to the number of pools.
inputFluxes	A TimeMap object consisting of a vector valued function describing the inputs to the pools as functions of time TimeMap.new.
solverfunc	The function used by to actually solve the ODE system.
pass	Forces the constructor to create the model even if it is invalid. If set to TRUE, does not enforce the requirements for a biologically meaningful model, e.g. does not check if negative values of respiration are calculated.

Value

Tr=getTransferMatrix(Anl) #this is a function of C and t

################################################################################# # build the two models (linear and nonlinear) mod=GeneralModel( t, A,iv, inputrates, deSolve.lsoda.wrapper) modnl=GeneralNlModel( t, Anl, iv, inputrates, deSolve.lsoda.wrapper)

Ynonlin=getC(modnl) lt1=2 lt2=4 plot(t,Ynonlin[,1],type="l",lty=lt1,col=1, ylab="Concentrations",xlab="Time",ylim=c(min(Ynonlin),max(Ynonlin))) lines(t,Ynonlin[,2],type="l",lty=lt2,col=2) legend("topleft",c("Pool 1", "Pool 2"),lty=c(lt1,lt2),col=c(1,2))

See Also

GeneralModel.

Examples

t_start=0
t_end=20
tn=100
timestep=(t_end-t_start)/tn
t=seq(t_start,t_end,timestep)
k1=1/2
k2=1/3
Km=0.5
nr=2

alpha=list()
alpha[["1_to_2"]]=function(C,t){
1/5
}
alpha[["2_to_1"]]=function(C,t){
1/6
}

f=function(C,t){
# The only thing to take care of is that we release a vector of the same
# size as C
S=C[[1]]
M=C[[2]]
O=matrix(byrow=TRUE,nrow=2,c(k1*M*(S/(Km+S)),
k2*M))
return(O)
}
Anl=new("TransportDecompositionOperator",t_start,Inf,nr,alpha,f)


c01=3
c02=2
iv=c(c01,c02)
inputrates=new("TimeMap",t_start,t_end,function(t){return(matrix(
nrow=nr,
ncol=1,
c( 2,  2)
))})
#################################################################################
# we check if we can reproduce the linear decomposition operator from the
# nonlinear one

SoilR documentation built on Oct. 13, 2023, 5:06 p.m.