Hi, I am totally new to both Julia and Optimization and I am trying to define a non linear objective that requires nested sums. I found some examples that I am trying to replicate, but I get an error. This is how I set my nested NLObjective

@NLobjective(my_model, :Min, Sum(Sum((Sum( m[i]* exp((X[j]-x[i])^2/gamma^2) * exp((Y[k]-y[i])^2/gamma^2) for i=1:np) - C[j,k])^2 for j in eachindex(X)) for k in eachindex(Y)))

Where m, x and y are my arrays of variables and X, Y and C are arrays of predefined parameters.

I am getting the following error and eBay help is hugely appreciated:

LoadError: Unsupported generator `:Sum`

Stacktrace:

[1] error(s::String)

@ Base ./error.jl:35

[2] _parse_generator_expression(code::Expr, x::Expr, operators::Set{Tuple{Symbol, Int64}})

@ JuMP ~/.julia/packages/JuMP/9CBpS/src/macros.jl:2008

[3] _parse_nonlinear_expression_inner(code::Expr, x::Expr, operators::Set{Tuple{Symbol, Int64}})

@ JuMP ~/.julia/packages/JuMP/9CBpS/src/macros.jl:1968

[4] _parse_nonlinear_expression(model::Expr, x::Expr)

@ JuMP ~/.julia/packages/JuMP/9CBpS/src/macros.jl:1876

[5] var"@NLobjective"(**source**::LineNumberNode, **module**::Module, model::Any, sense::Any, x::Any)

@ JuMP ~/.julia/packages/JuMP/9CBpS/src/macros.jl:2393

in expression starting at /Users/Greg/Documents/OneDrive/Documents/Julia Code/Scalar points optimizer:41

in expression starting at /Users/Greg/Documents/OneDrive/Documents/Julia Code/Scalar points optimizer:41