Running examples in ‘RxODE-Ex.R’ failed
The error most likely occurred in:

> ### Name: RxODE
> ### Title: Create an ODE-based model specification
> ### Aliases: RxODE
> ### Keywords: models nonlinear
> 
> ### ** Examples
> 
> # Step 1 - Create a model specification
> ode <- "
+    # A 4-compartment model, 3 PK and a PD (effect) compartment
+    # (notice state variable names 'depot', 'centr', 'peri', 'eff')
+ 
+    C2 = centr/V2;
+    C3 = peri/V3;
+    d/dt(depot) =-KA*depot;
+    d/dt(centr) = KA*depot - CL*C2 - Q*C2 + Q*C3;
+    d/dt(peri)  =                    Q*C2 - Q*C3;
+    d/dt(eff)  = Kin - Kout*(1-C2/(EC50+C2))*eff;
+ "
> 
> m1 <- RxODE(model = ode, modName = "m1")
> print(m1)
RxODE model named "m1" (ready to run).
States: depot, centr, peri, eff
Params: V2, V3, KA, CL, Q, Kin, Kout, EC50
> 
> # Step 2 - Create the model input as an EventTable,
> # including dosing and observation (sampling) events
> 
> # QD (once daily) dosing for 5 days.
> 
> qd <- eventTable(amount.units = "ug", time.units = "hours")
> qd$add.dosing(dose = 10000, nbr.doses = 5, dosing.interval = 24)
> 
> # Sample the system hourly during the first day, every 8 hours
> # then after
> 
> qd$add.sampling(0:24)
> qd$add.sampling(seq(from = 24+8, to = 5*24, by = 8))
> 
> # Step 3 - set starting parameter estimates and initial
> # values of the state
> 
> theta <-
+     c(KA = .291, CL = 18.6,
+       V2 = 40.2, Q = 10.5, V3 = 297.0,
+       Kin = 1.0, Kout = 1.0, EC50 = 200.0)
> 
> # init state variable
> inits <- c(0, 0, 0, 1);
> 
> # Step 4 - Fit the model to the data
> 
> qd.cp <- m1$solve(theta, events = qd, inits)
Warning in rxInits(dll, inits, state, 0) :
  Assumed order of inputs: depot, centr, peri, eff
Error in .sexp(params, inits, as.double(scale), lhs_vars, time, evid,  : 
  INTEGER() can only be applied to a 'integer', not a 'symbol'
Error in .sexp(params, inits, as.double(scale), lhs_vars, time, evid,  : 
  INTEGER() can only be applied to a 'integer', not a 'symbol'
Error in m1$solve(theta, events = qd, inits) : 
  Tried both LSODA and DOP853, but could not solve the system.
Execution halted