# Initial guess in MINLP

**URL:** <https://discourse.julialang.org/t/initial-guess-in-minlp/22223>\
**Category:** Optimization (Mathematical)\
**Created:** [March 22, 2019, 10:24pm UTC](https://discourse.julialang.org/t/initial-guess-in-minlp/22223 "2019-03-22T22:24:43Z")\
**Posts on this page:** 5\
**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 22, 2019, 10:24pm UTC](https://discourse.julialang.org/t/initial-guess-in-minlp/22223/1 "2019-03-22T22:24:43Z")

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Hello,  
Something strange happens with my program.

using JuMP, Ipopt, CPLEX, Juniper  
m = Model(solver=juniper)  
@variable(m, x, start = 0.0)  
@variable(m, y, start = 0.0)  
@NLobjective(m, Min, sin((1-5x))^2 + 100(cos(y-x^2))^2)  
solve(m)  
println("x = ", getvalue(x), " y = ", getvalue(y))

where, I set the initial guess to x = 0 and y = 0. The solution provided is

Obj: 7.434409052608867e-20  
x = 0.828318530664551 y = -0.8846847385581247

I want to resolve this MINLP and change the starting point to optimize. However, when I change the starting point, the optimal solution obtained is the same. This not happen.

Can anybody help me or give a advise how can I set the initial guess in MINLP?

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**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 22, 2019, 10:28pm UTC](https://discourse.julialang.org/t/initial-guess-in-minlp/22223/2 "2019-03-22T22:28:30Z")

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It doesn’t look like Juniper supports warm-starts:

> <https://github.com/lanl-ansi/Juniper.jl/blob/5d99279f7c7f3f723419a58dedc7ab963aeb6108/src/model.jl#L224>

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**Author:** ![ccoffrin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ccoffrin/32/400_2.png) [@ccoffrin](https://discourse.julialang.org/u/ccoffrin)\
**Post date:** [March 24, 2019, 3:00am UTC](https://discourse.julialang.org/t/initial-guess-in-minlp/22223/3 "2019-03-24T03:00:44Z")

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This should be a fairly straightforward feature to add. I would recomend posting a feature request as an Issue in the Juniper repo.

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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 24, 2019, 1:35pm UTC](https://discourse.julialang.org/t/initial-guess-in-minlp/22223/4 "2019-03-24T13:35:55Z")

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Der collegue,  
How can I do this? Is there a Juniper repo?  
Thank you!

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**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 24, 2019, 4:59pm UTC](https://discourse.julialang.org/t/initial-guess-in-minlp/22223/5 "2019-03-24T16:59:00Z")

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Go to [https://github.com/lanl-ansi/Juniper.jl/issues](https://github.com/lanl-ansi/Juniper.jl/issues) and click “New issue”