I’m trying to use Optim and `Fminbox()`

for model fitting, but get an error message – and wonder what I do wrong. Here is what I do:

I have created a loss function `loss(p)`

(squared norm of shooting error for ODE). As my initial guess, I have `pvec`

given as:

```
julia> pvec
1-element Array{Real,1}:
0.45
```

The loss function at the initial guess is:

```
julia> loss(pvec)
2.9500373651496017
```

I can plot the function:

```
P = range(pvec[1]*0.1,pvec[1]*50,length=100)
plot(P,loss.(P))
```

leading to:

I have defined lower and upper bounds:

```
p_lo = pvec*0.1;
p_up = pvec*100;
```

`using Optim`

, I try to optimize the loss function:

```
julia> optimize(loss,p_lo,p_up,pvec,Fminbox())
MethodError: no method matching optimize(::getfield(Main, Symbol("##76#77")), ::Array{Float64,1}, ::Array{Float64,1}, ::Array{Real,1}, ::Fminbox{LBFGS{Nothing,LineSearches.InitialStatic{Float64},LineSearches.HagerZhang{Float64,Base.RefValue{Bool}},getfield(Optim, Symbol("##22#24"))},Float64,getfield(Optim, Symbol("##46#48"))})
Closest candidates are:
optimize(::Any, ::AbstractArray{T<:AbstractFloat,N} where N, ::AbstractArray{T<:AbstractFloat,N} where N, !Matched::AbstractArray{T<:AbstractFloat,N} where N, ::Fminbox) where T<:AbstractFloat at C:\Users\user_name\.julia\packages\Optim\Agd3B\src\multivariate\solvers\constrained\fminbox.jl:163
optimize(::Any, ::AbstractArray{T<:AbstractFloat,N} where N, ::AbstractArray{T<:AbstractFloat,N} where N, !Matched::AbstractArray{T<:AbstractFloat,N} where N, ::Fminbox, !Matched::Any; inplace, autodiff) where T<:AbstractFloat at C:\Users\user_name\.julia\packages\Optim\Agd3B\src\multivariate\solvers\constrained\fminbox.jl:163
optimize(::Any, ::AbstractArray, ::AbstractArray, ::AbstractArray, !Matched::SAMIN) at C:\Users\user_name\.julia\packages\Optim\Agd3B\src\multivariate\solvers\constrained\samin.jl:60
...
Stacktrace:
[1] top-level scope at In[189]:1
```

Question: what is it that I miss?