| GeneralNlModel {SoilR} | R Documentation |
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.
GeneralNlModel( t, TO, ivList, inputFluxes, solverfunc = deSolve.lsoda.wrapper, pass = FALSE )
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
|
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. |
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))
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