# Save optimum variables

**URL:** <https://discourse.julialang.org/t/save-optimum-variables/36405>\
**Category:** Optimization (Mathematical)\
**Created:** [March 23, 2020, 8:47pm UTC](https://discourse.julialang.org/t/save-optimum-variables/36405 "2020-03-23T20:47:41Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![angeloaliano1](https://avatars.discourse-cdn.com/v4/letter/a/7ea924/32.png) [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Post date:** [March 23, 2020, 8:47pm UTC](https://discourse.julialang.org/t/save-optimum-variables/36405/1 "2020-03-23T20:47:41Z")

</div>

Dear all, I have the following optimization problem implemented:

```julia
using JuMP, CPLEX, Printf
n=50

function Problem(c)
    modelo = Model(with_optimizer(CPLEX.Optimizer))

    (n, n) = size(c)

    @variable(modelo, x[1:n,1:n], Bin)
    @objective(modelo, Min, sum(sum(c[i,j]*x[i,j] for j=1:n) for i=1:n) )
    @constraints modelo begin
        c1[i=1:n], sum(x[i,j] for j=1:n) == 10
        c2[j=1:n], sum(x[i,j] for i=1:n) == 10
    end

    status=optimize!(modelo)
    X=value.(x)
    return X
end

for i=1:10
     c=-2 .+ round.(7*rand(n,n))
     XStar = Problem(c)
end

```

There is a simple way to save the optimum variables “XStar” in 10 different archives (.jl or .dat) whose name depends of counter “i”?  
Best regards.

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<div class="post-metadata">

**Author:** ![hendri54](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/hendri54/32/9621_2.png) [@hendri54](https://discourse.julialang.org/u/hendri54)\
**Post date:** [March 23, 2020, 10:09pm UTC](https://discourse.julialang.org/t/save-optimum-variables/36405/2 "2020-03-23T22:09:49Z")

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Are you looking for binary (e.g., JLD2) or text representation (e.g., CSV)?

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<div class="post-metadata">

**Author:** ![angeloaliano1](https://avatars.discourse-cdn.com/v4/letter/a/7ea924/32.png) [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Post date:** [March 23, 2020, 10:24pm UTC](https://discourse.julialang.org/t/save-optimum-variables/36405/3 "2020-03-23T22:24:59Z")

</div>

For binary. I need to manipulate this solution in a future.

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<div class="post-metadata">

**Author:** ![odow](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/odow/32/28685_2.png) [@odow](https://discourse.julialang.org/u/odow)\
**Post date:** [March 23, 2020, 11:46pm UTC](https://discourse.julialang.org/t/save-optimum-variables/36405/4 "2020-03-23T23:46:50Z")

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If “in future” you mean the same version of Julia, then:

```nohighlight
using Serialization
X = rand(3, 3)
i = 1
open("my_file_$(i)", "w") do io
    serialize(io, X)
end

Y = open(deserialize, "my_file_$(i)", "r")

X == Y # true

```

Otherwise you will need to look into JLD2 ([GitHub - JuliaIO/JLD2.jl: HDF5-compatible file format in pure Julia](https://github.com/JuliaIO/JLD2.jl)) or similar.