[R] Ode error message

[Raphaëlle Carraud]

Hello,

I am creating a program with R to solve a differential equation system. However, I get the following message I do not understand :

> out <- ode(y = state, times = z, func = liquide, parms = 0, atol = 0)
DLSODA-  EWT(I1) is R1 .le. 0.0
In above message, I1 = 1
 
In above message, R1 = 0
 
Error in lsoda(y, times, func, parms, ...) : 
  illegal input detected before taking any integration steps - see written message

or this one when I tried modifying the atoll value :

> out <- ode(y = state, times = z, func = liquide, parms = 0, atol = 10^-14)
DLSODA-  Warning..Internal T (=R1) and H (=R2) are
      such that in the machine, T + H = T on the next step
     (H = step size). Solver will continue anyway.
In above message, R1 = 0, R2 = 0
 
DINTDY-  T (=R1) illegal
In above message, R1 = 1
 
      T not in interval TCUR - HU (= R1) to TCUR (=R2)
In above message, R1 = 0, R2 = 0
 
DINTDY-  T (=R1) illegal
In above message, R1 = 2
 
      T not in interval TCUR - HU (= R1) to TCUR (=R2)
In above message, R1 = 0, R2 = 0
 
DLSODA-  Trouble in DINTDY.  ITASK = I1, TOUT = R1
In above message, I1 = 1
 
In above message, R1 = 2

Here is my program. I also tried changing the initial values but it does not work well.

liquide <- function(z, state, parameters) {
  with(as.list(c(state,parameters)),{
    # rate of change
      
    Tr <- 273+90
    C <- CA + CB + CC + CD + CE + CI + CG + CJ + CK + CH
    
    K32 <- 6.54*10^4      
    K33 <- 1.37*10^4      
    K34 <- 330                 
    K35 <- 5.81*10^4      
    kf2 <- 1.37*10^3      
    kf3 <- 1.37*10^3     
    kf4 <- 8.68*10^5      
    kf5 <- 157.2
    
    K2 <- 10^1.37        
    K3 <- 10^(-3.35)     
    
    r1 <- kf4*CD - kf4/K34*CE^2
    r2 <- kf3*CA*CB - kf3/K33*CD
    r3 <- kf2*CA^2 - kf2/K32*CC
    r4 <- kf5*CC - kf5/K35*CE*CI^2 
    
    
    dCA <- -r2                                                      # dNO/dt
    dCB <- -r3 - r2                                               # dNO2/dt
    dCC <- r3/2 - r4                                             # dN2O4/dt
    dCD <- r2 - r1                                                # dN2O3/dt
    dCE <- 2*r1 + r4                                            # dHNO2/dt
    dCI <- r4                                                         # dHNO3/dt
    dCG <- -r4 - r1                                               # dH2O/dz
    dCH <- (dCE + dCI)/((K2 + K3)*(CE + CI))      # dH/dz
    dCJ <-  (CH*dCI - CI*dCH)/(K3*CH^2)          # dNO3-/dz
    dCK <-  (CH*dCE - CE*dCH)/(K2*CH^2)        # dNO2-/dz
    
   
    
    list(c(dCA, dCB, dCC, dCD, dCE, dCI, dCG, dCH, dCJ, dCK))
  })   # end with(as.list ...
}


Ti <- 273+90       # K
Ct <- 5100   # mol/m^3

state <-c(CA = 0,           # mol/m^3 NO2
          CB = 0,               # mol/m^3 NO
          CC = 0,                # mol/m^3 N2O4
          CD = 0,              # mol/m^3 N2O3
          CE = 50,              # mol/m^3 HNO2
          CI = 50,             # mol/m^3 HNO3
          CG = 5000,         # mol/m^3 H2O
          CH = 0,             # mol/m^3 H+
          CJ = 0,                # mol/m^3 NO3-
          CK = 0)             # mol/m^3 NO2-
          
parameters <- c(Ct = 5100)

z <- seq(0, 15, by = 1)  # en seconde

library(deSolve)
out <- ode(y = state, times = z, func = liquide, parms = 0, atol = 10^-14)
head(out)
plot(out)

Thank you