# NLOPT forced stop with two constraints
**URL:** https://discourse.julialang.org/t/nlopt-forced-stop-with-two-constraints/115371
**Category:** Optimization (Mathematical)
**Tags:** nlopt
**Created:** [June 8, 2024, 9:09pm UTC](https://discourse.julialang.org/t/nlopt-forced-stop-with-two-constraints/115371 "2024-06-08T21:09:50Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@mary](https://discourse.julialang.org/u/mary)
#### Post date: [June 8, 2024, 9:09pm UTC](https://discourse.julialang.org/t/nlopt-forced-stop-with-two-constraints/115371/1 "2024-06-08T21:09:50Z")
Hi
I am using NLOPT with two inequality constraints. It can do the optmization when I suppress the second constraint but with two constraints it stops after 1st iteration with forced stop. I also run objective function and constraints out of the Nlopt and they are fine. do you have any idea on this issue? NLopt can handle two constraints or not?
```julia
function gf_p_optimize(p_init; r, β, η, TOL=1e-4, MAX_ITER, fem_params)
opt = Opt(:LD_MMA, fem_params.np)
opt.lower_bounds = 1e-5
opt.upper_bounds = 1
opt.xtol_rel = TOL
opt.maxeval = MAX_ITER
iteration_counter = 0
iteration_solutions = Any[]
function objective_fn(p0, grad)
iteration_counter += 1
push!(iteration_solutions, p0)
pf_vec = pf_p0(iteration_solutions[iteration_counter]; r, fem_params)
return gf_p(p0, grad;iteration_counter, r, β, η, fem_params)
end
opt.min_objective = (p0, grad) -> objective_fn(p0, grad)
inequality_constraint!(opt, (p0, gradc) -> cf_p(p0, gradc; r, β, η, fem_params), 1e-8)
inequality_constraint!(opt, (p0, gradw) -> wf_p(p0, gradw; r, β, η, fem_params), 1e-8)
(g_opt, p_opt, ret) = optimize(opt, p_init)
@show numevals = opt.numevals # the number of function evaluations
println("got $g_opt at $p_opt after $numevals iterations (returned $ret)")
return g_opt, p_opt
end
```
---
### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [June 8, 2024, 11:56pm UTC](https://discourse.julialang.org/t/nlopt-forced-stop-with-two-constraints/115371/2 "2024-06-08T23:56:11Z")
Yes, NLopt can handle multiple constraints. There must be a error in your `wf_p` function.
Do you have a reproducible example?
---
### Author:  [@mary](https://discourse.julialang.org/u/mary)
#### Post date: [June 9, 2024, 12:03am UTC](https://discourse.julialang.org/t/nlopt-forced-stop-with-two-constraints/115371/3 "2024-06-09T00:03:07Z")
wf\_p can show the output out of the NLopt.
```julia
function wf_p(p0::Vector, gradw::Vector;iteration_counter, r, β, η, fem_params)
if length(gradw) > 0
#grad calculation
gradw[:] = assemble_vector(grad_temp,fem_params.Pf)
end
wset = 80
cons_temp(dp)=∫(( ((p->Em(p))∘pfh) * (jfuntN∘(ε(uh),sh,ε(uhp))) )*dp)fem_params.dΩ
cons=sum(assemble_vector(cons_temp,fem_params.Pf))
wo = wset - cons
open("constraintwork.txt", "a") do io
write(io, "$wo \n")
end
return wo
end
```
this is the function I have used.
---
### Author:  [@odow](https://discourse.julialang.org/u/odow)
#### Post date: [June 9, 2024, 12:06am UTC](https://discourse.julialang.org/t/nlopt-forced-stop-with-two-constraints/115371/4 "2024-06-09T00:06:51Z")
Do you have the full stack trace of the error? Have you updated to the latest version of NLopt.jl?
To be able to help, we really need a reproducible example of your code that someone can copy-paste into their REPL and reproduce the error. It’s hard to spot something wrong from just this snippet.