# How to set lower and upper bound for SimulatedAnnealing OptimizationProblem's? Tired "lu=" and "ub=" but doesn't seem to work
**URL:** https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134
**Category:** Optimization (Mathematical)
**Created:** [October 3, 2021, 9:13am UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134 "2021-10-03T09:13:51Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@Torkel](https://discourse.julialang.org/u/Torkel)
#### Post date: [October 3, 2021, 9:13am UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134/1 "2021-10-03T09:13:51Z")
This is the sampel code:
```julia
using GalacticOptim, Optim
function tmp(x,p)
return (x[1]-2)^2
end
prob = OptimizationProblem(tmp,[4.],lb=[3],ub=[6])
res = solve(prob,SimulatedAnnealing())
```
the result is correct `1.9982228757130818`. However, I set a lower bound `=3`, so would expect it to step here. How do I get the lower bound to work?
Similarily, for:
```julia
using GalacticOptim, Optim
function tmp(x,p)
return -(x[1]-2)^2
end
prob = OptimizationProblem(tmp,[4.],lb=[3],ub=[6])
res = solve(prob,SimulatedAnnealing())
```
I would expect to just hit the upper bound, but I get the answer `400.7172021819915`.
Am I missing something obvious here?
(also at [https://github.com/SciML/GalacticOptim.jl/issues/171](https://github.com/SciML/GalacticOptim.jl/issues/171))
---
### Author:  [@goerch](https://discourse.julialang.org/u/goerch)
#### Post date: [October 3, 2021, 11:04am UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134/2 "2021-10-03T11:04:31Z")
The modified program
```julia
using GalacticOptim, Optim
function tmp(x,p)
return (x[1]-2)^2
end
fun = OptimizationFunction(tmp, GalacticOptim.AutoForwardDiff())
prob = OptimizationProblem(fun,[4.],lb=[3],ub=[6])
res = solve(prob,Fminbox())
println(res)
using GalacticOptim, Optim
function tmp(x,p)
return -(x[1]-2)^2
end
fun = OptimizationFunction(tmp, GalacticOptim.AutoForwardDiff())
prob = OptimizationProblem(fun,[4.],lb=[3],ub=[6])
res = solve(prob,Fminbox())
println(res)
```
returns
```julia
retcode: Default
u: [3.0000000013333334]
Final objective value: 1.0000000026666669
retcode: Default
u: [5.999999999666667]
Final objective value: -15.999999997333333
```
Furthermore Optim.jl’s documentation [https://github.com/JuliaNLSolvers/Optim.jl/blob/adc5b277b3f915c25233b45f8f2dd61006815e63/docs/src/algo/simulated\_annealing.md](https://github.com/JuliaNLSolvers/Optim.jl/blob/adc5b277b3f915c25233b45f8f2dd61006815e63/docs/src/algo/simulated_annealing.md)
does not mention support for bounds. This looks like a documentation problem to me.
---
### Author:  [@Torkel](https://discourse.julialang.org/u/Torkel)
#### Post date: [October 3, 2021, 11:41am UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134/3 "2021-10-03T11:41:33Z")
I found out about the bounds at [OptimizationProblem · GalacticOptim.jl](https://galacticoptim.sciml.ai/stable/API/optimization_problem/), but you might be right and those not applying to the SimulatedAnnealing algorithm.
I have a problem where derivatives don’t make sense, so I figured I was limited to that one and NelderMead ([https://galacticoptim.sciml.ai/stable/local\_optimizers/local\_derivative\_free/](https://galacticoptim.sciml.ai/stable/local_optimizers/local_derivative_free/)), which I ran into other problems with (it errors at the HPC I have access to, I’ve asked the HPC people for help with interpreting the error message the HPC yielded).
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [October 3, 2021, 11:49am UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134/4 "2021-10-03T11:49:36Z")
Open an issue. GalacticOptim should just wrap the algorithm in an FMinBox automatically if you add bounds.
---
### Author:  [@Torkel](https://discourse.julialang.org/u/Torkel)
#### Post date: [October 3, 2021, 12:07pm UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134/5 "2021-10-03T12:07:13Z")
Got it 👍
---
### Author:  [@mcreel](https://discourse.julialang.org/u/mcreel)
#### Post date: [October 3, 2021, 4:32pm UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134/6 "2021-10-03T16:32:59Z")
There is a bounded simulated annealing algorithm in Optim.jl called SAMIN. An example of how to call it would be
` opt = Optim.optimize(obj, lb, ub, θ, SAMIN())`
where ib, ub and θ are all vectors.
---
### Author:  [@Torkel](https://discourse.julialang.org/u/Torkel)
#### Post date: [October 3, 2021, 5:42pm UTC](https://discourse.julialang.org/t/how-to-set-lower-and-upper-bound-for-simulatedannealing-optimizationproblems-tired-lu-and-ub-but-doesnt-seem-to-work/69134/7 "2021-10-03T17:42:03Z")
Thanks for pointing that out, I will try to get it to work.