[R] Error in eval(expr, envir, enclos) : object 'N' not found

[hansoffate]

Oh yes, that's true, but I don't understand why the same exact model works
fine the first time I run LSODA, then running the model again with different
PARMS causes it to error  with this error.  I've been trying to debug or
find other relevant posts with this same error, but so far I have had no
lucky.  

Any help would be appreciated.
-Hans


Uwe Ligges-3 wrote:
> 
> 
> 
> hansoffate wrote:
>> I'm running an LSODA to generate some graphs, but I need to stop at a
>> certain
>> point and use those values to generate another LSODA output.  This is
>> working fine, but when I try to run the second LSODA, I get the "Error in
>> eval(expr, envir, enclos) : object 'N' not found".  Any ideas what can be
>> causing this? I have no object 'N' anywhere in the script.  
> 
> At least I see capital N in both model and model2 - roughly 10 times ...
> 
> Uwe Ligges
> 
> 
> 
> I made an
>> identical version of models states, parameters, and everything just by
>> adding 2 after each one, and I'm still getting this error.  
>> 
>> Thanks,
>> -Hans
>> 
>> ::CODE::
>> require(odesolve);
>> ###Params for running script ##
>> iniT=1E3; iniN=10; iniM=0; iniC=1E3;
>> num_days = 30; interval_size = .1; OF_prcnt = .10;
>> 
>> model <- function(t, state, pars)
>> {
>>   with (as.list(c(state, pars)), {
>> 	dT=(a*T-a*T*b*T) - (c1*N*T) - (Kt*M*T)
>> 	dN=a1 - (f*N) + g * (T/(h+T)) * N - (p * N * T) - (Kn * M * N)
>> 	dC=a2 - (beta * C) - (Kc * M  * C)
>> 	dM= -(gamma) * M + Vm 
>> 	
>>     return(list(c(dT,dN,dC,dM)))
>>   })
>> }
>> 
>> model2 <- function(t, state2, pars2)
>> {
>>   with (as.list(c(state2, pars2)), {
>> 	dT=(a*T-a*T*b*T) - (c1*N*T) - (Kt*M*T)
>> 	dN=a1 - (f*N) + g * (T/(h+T)) * N - (p * N * T) - (Kn * M * N)
>> 	dC=a2 - (beta * C) - (Kc * M  * C)
>> 	dM= -(gamma) * M + Vm 
>> 	
>>     return(list(c(dT,dN,dC,dM)))
>>   })
>> }
>> 
>> ### First Half - Tumor growth to 10%
>> pars <- list( Tini=iniT, Nini=iniN, Mini=iniM, Cini=iniC,
>> 		  a=4.31E-3, b=1.02E-14, c1=3.41E-10, Kt=8E-1,
>>               f=4.12E-2, g=1.5E-2, h=2.02E1, beta=1.20E-2, gamma=9E-1,
>> 		  Kc=6E-1, Kn=6E-1, p=2E-11, a1=1.2E4, a2=7.5E8, Vm=0 )
>> 
>> tout    <- seq(0, num_days, by=interval_size)
>> state   <- c(T = pars$Tini, N = pars$Nini, C = pars$Cini, M = pars$Mini)
>> out     <- lsoda(state, tout, model, pars)
>> 
>> ## Finding position at which OF function is reached
>> final_matrix = out;
>> loopsize = (num_days / interval_size) + 1
>> OF_tumor_size = iniT + (OF_prcnt * iniT)
>> 
>> ## Sentinel Value to find at which row in the matrix reaches
>> OF_tumor_size
>> OF_row=-1;  
>> for(i in 1:loopsize) {
>>   if( out[i,2] >= OF_tumor_size) {
>>     OF_row=i;
>>     break;
>>   }
>> }
>> 
>> if(OF_row != -1) {
>>   ##Params setup
>>   OF_iniT=out[OF_row,2]; OF_iniN=out[OF_row,3]; OF_iniC=out[OF_row,4];
>> OF_iniM=out[OF_row,5];
>>   pars2 <- list( Tini=OF_iniT, Nini=OF_iniN, Mini=OF_iniM, Cini=OF_iniC,
>> 	          a=4.31E-3, b=1.02E-14, c1=3.41E-10, Kt=8E-1,
>>                 f=4.12E-2, g=1.5E-2, h=2.02E1, beta=1.20E-2, gamma=9E-1,
>> 		    Kc=6E-1, Kn=6E-1, p=2E-11, a1=1.2E4, a2=7.5E8, Vm=0 )
>>   state2   <- c(T = pars2$Tini, N = pars2$Nini, C = pars2$Cini, M =
>> pars2$Mini)
>>   out2     <- lsoda(state2, tout, model2, pars2)
>> }
>>
> 
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