Maximum Likelihood Estimation

New to Julia
,
1

Hi all,

I’ve been into Julia for a week now. I managed to transfer all my code from R to Julia and the results I obtain in Julia are what I expect.

However, when I try to obtain the maximum likelihood estimates from my function (which doesn’t have a closed form expression, it is constructed from numerical integration basically) using Optim.optimize, it immediately returns NaN, when I know it can’t be NA because I do get results in R.

I get this error

ERROR: LoadError: InexactError: Int64(NaN)
Stacktrace:
 [1] Int64(::Float64) at ./float.jl:710
 [2] x_of_nans(::Array{Int64,1}, ::Type{T} where T) at /home/andrel/.julia/packages/NLSolversBase/QPnui/src/NLSolversBase.jl:60 (repeats 2 times)
 [3] NonDifferentiable(::Function, ::Array{Int64,1}, ::Int64; inplace::Bool) at /home/andrel/.julia/packages/NLSolversBase/QPnui/src/objective_types/nondifferentiable.jl:11
 [4] NonDifferentiable(::Function, ::Array{Int64,1}, ::Int64) at /home/andrel/.julia/packages/NLSolversBase/QPnui/src/objective_types/nondifferentiable.jl:11
 [5] promote_objtype(::NelderMead{Optim.AffineSimplexer,Optim.AdaptiveParameters}, ::Array{Int64,1}, ::Symbol, ::Bool, ::Function) at /home/andrel/.julia/packages/Optim/onG5j/src/multivariate/optimize/interface.jl:63
 [6] optimize(::Function, ::Array{Int64,1}; inplace::Bool, autodiff::Symbol, kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /home/andrel/.julia/packages/Optim/onG5j/src/multivariate/optimize/interface.jl:86
 [7] optimize(::Function, ::Array{Int64,1}) at /home/andrel/.julia/packages/Optim/onG5j/src/multivariate/optimize/interface.jl:84
 [8] top-level scope at /home/andrel/Desktop/PhD/1st Year/Julia/Functions_Attempt2.jl:114
in expression starting at /home/andrel/Desktop/PhD/1st Year/Julia/Functions_Attempt2.jl:114

Do you know what is happening or if there is any other package that I can use?

Many thanks

2

Hi Maria, please could you provide the code that produces this error? It would greatly help if we could reproduce it ourselves.

3

This looks like you’re maybe using ints when you should use floats. In R, 1 is a float, not an int. In Julia, 1 is an int and 1.0 is a float.

4

Thanks! It seems to have worked now (I do have some errors but it’s in my other functions)