In the following script I try to use a single function that will be

used in multiroot and jacobian.full.

But it is impossible for me, the function for one case must revert a vector and for another a list. As I have commented on the body of the function.

What would be a possible solution. Or should I use another package; for example numDeriv :: jacobian?

```
library(rootSolve)
sys <- function( y, parms) {
with(as.list(c(y,parms)),{
dy = a*(1 + b*(y[2] - 1)/(c + y[2] - 1) - 1*y[1])
dz = 1*y[1] - y[2]
#to multiroot, it must return a vector with as many values as the length of start
return(c(dy, dz))
#to jacobian,function that calculates one function value for each element of y
return(list(c(dy, dz))
})
}
parms <- list(a = 1, b = 1, c= 2)
ic=multiroot(f=sys, start=c(-1, 18), parms = parms)
ic$root
jacobian.full(y = ic$root, func =sys, parms = parms)
library(deSolve)
ode <- deSolve::ode(y = c( 1, 0),
times = seq(1,100),
func = sys,
parms = parms)
plot(ode)
```