# \#jump

**URL:** https://discourse.julialang.org/tag/jump/28.md

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## [ANN: JuMP-dev 2027](https://discourse.julialang.org/t/ann-jump-dev-2027/139867)

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**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 0\
**Last updated:** [October 6, 2026, 11:00pm UTC](https://discourse.julialang.org/t/ann-jump-dev-2027/139867 "2026-10-06T23:00:21Z")

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Dear all, We’ve got exciting news for the world of open source mathematical optimization! We’re pleased to announce that JuMP-dev 2027 will be co-located with the CVXPY Workshop 2027 and the HiGHS Workshop 2027. The wo…

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## [\[ANN\] PortfolioOptimisers.jl: Ape together strong](https://discourse.julialang.org/t/ann-portfoliooptimisers-jl-ape-together-strong/133099)

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**Author:** [@dcelisgarza](https://discourse.julialang.org/u/dcelisgarza)\
**Replies:** 17\
**Last updated:** [September 27, 2026, 3:21pm UTC](https://discourse.julialang.org/t/ann-portfoliooptimisers-jl-ape-together-strong/133099 "2026-09-27T15:21:47Z")

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PortfolioOptimisers.jl Editorial note: If you read this post and then go to the docs’ homepage or the package’s readme and they seem familiar, it’s because I started writing this before I had a proper readme. Portfolio …

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## [\[ANN\] ModelPredictiveControl.jl](https://discourse.julialang.org/t/ann-modelpredictivecontrol-jl/100147)

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**Author:** [@franckgaga](https://discourse.julialang.org/u/franckgaga)\
**Replies:** 82\
**Last updated:** [September 25, 2026, 7:56pm UTC](https://discourse.julialang.org/t/ann-modelpredictivecontrol-jl/100147 "2026-09-25T19:56:38Z")

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ModelPredictiveControl.jl I’m currently writing a model predictive control package for Julia. Here’s a quick list of the main features: Both linear and nonlinear plant models are supported. The implementation exploi…

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## [In my JuMP model, the LP file preserves the original variable names, but the MPS file appears to rename them, so how can I map the Gurobi .sol solution back to the original JuMP variables?](https://discourse.julialang.org/t/in-my-jump-model-the-lp-file-preserves-the-original-variable-names-but-the-mps-file-appears-to-rename-them-so-how-can-i-map-the-gurobi-sol-solution-back-to-the-original-jump-variables/139462)

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**Author:** [@amit\_97](https://discourse.julialang.org/u/amit_97)\
**Replies:** 2\
**Last updated:** [September 14, 2026, 10:19pm UTC](https://discourse.julialang.org/t/in-my-jump-model-the-lp-file-preserves-the-original-variable-names-but-the-mps-file-appears-to-rename-them-so-how-can-i-map-the-gurobi-sol-solution-back-to-the-original-jump-variables/139462 "2026-09-14T22:19:23Z")

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Hi everyone, I’m generating both .lp and .mps files from the same JuMP model using Gurobi. In the LP file, the original JuMP variable names are preserved, for example: 1200 x2\[1,(1,\_0)\] - 41054.62117964038 B2\[1,(1,\_0)…

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## [Ipopt has trouble with \`Vector{AffExpr} in MOI.Zeros\`](https://discourse.julialang.org/t/ipopt-has-trouble-with-vector-affexpr-in-moi-zeros/138395)

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**Author:** [@bernardofpc](https://discourse.julialang.org/u/bernardofpc)\
**Replies:** 10\
**Last updated:** [August 8, 2026, 8:30am UTC](https://discourse.julialang.org/t/ipopt-has-trouble-with-vector-affexpr-in-moi-zeros/138395 "2026-08-08T08:30:50Z")

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I have a JuMP model where solving with HiGHS and Ipopt results in different objective\_values. A JuMP Model ├ solver: Ipopt ├ objective\_sense: MIN\_SENSE │ └ objective\_function\_type: AffExpr ├ num\_variables: 54 ├ num\_cons…

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## [Improving JuMP for AI agents](https://discourse.julialang.org/t/improving-jump-for-ai-agents/138437)

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**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 6\
**Last updated:** [August 3, 2026, 3:38pm UTC](https://discourse.julialang.org/t/improving-jump-for-ai-agents/138437 "2026-08-03T15:38:10Z")

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Attention JuMP users! In the last release we spent some time improving JuMP for use by AI agents. Error messages are now clearer and include an actionable next step, which helps agents debug issues. (This also helps reg…

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## [Decomposing a scenario-feasibility MILP with binary recourse in JuMP](https://discourse.julialang.org/t/decomposing-a-scenario-feasibility-milp-with-binary-recourse-in-jump/137898)

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**Author:** [@decomp-lab](https://discourse.julialang.org/u/decomp-lab)\
**Replies:** 10\
**Last updated:** [July 5, 2026, 10:52pm UTC](https://discourse.julialang.org/t/decomposing-a-scenario-feasibility-milp-with-binary-recourse-in-jump/137898 "2026-07-05T22:52:47Z")

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I have a two-stage multi-scenario MILP in JuMP with an inventory/order-flow structure. The first-stage variables are shared across all scenarios. Each scenario then has its own continuous flow variables and binary timin…

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## [Hexaly solver with JuMP](https://discourse.julialang.org/t/hexaly-solver-with-jump/124827)

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**Author:** [@baprata](https://discourse.julialang.org/u/baprata)\
**Replies:** 8\
**Last updated:** [June 26, 2026, 7:45pm UTC](https://discourse.julialang.org/t/hexaly-solver-with-jump/124827 "2026-06-26T19:45:57Z")

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Dear Colleagues, Is it feasible to call the Hexaly solver (https://www.hexaly.com/) within the JuMP library? If so, could someone provide some source code with an example? Best regards, Bruno

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## [Memory blow-up when solving a sparse affine Hermitian SDP translated from YALMIP to JuMP](https://discourse.julialang.org/t/memory-blow-up-when-solving-a-sparse-affine-hermitian-sdp-translated-from-yalmip-to-jump/137744)

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**Author:** [@hz-xiaxz](https://discourse.julialang.org/u/hz-xiaxz)\
**Replies:** 10\
**Last updated:** [June 23, 2026, 7:24am UTC](https://discourse.julialang.org/t/memory-blow-up-when-solving-a-sparse-affine-hermitian-sdp-translated-from-yalmip-to-jump/137744 "2026-06-23T07:24:42Z")

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Hi JuMP developers, I am translating a MATLAB/YALMIP semidefinite program to Julia/JuMP + MosekTools. The model comes from a many-body bootstrap calculation. The MATLAB/YALMIP version can solve a small 3 x 3 lattice cas…

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## [ANN: JuMP-dev 2026 talk recordings](https://discourse.julialang.org/t/ann-jump-dev-2026-talk-recordings/137627)

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**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 0\
**Last updated:** [June 14, 2026, 10:27pm UTC](https://discourse.julialang.org/t/ann-jump-dev-2026-talk-recordings/137627 "2026-06-14T22:27:41Z")

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Hi all, Talk recordings from JuMP-dev 2026 are rolling out on this playlist. Check them out here: Cheers, Oscar

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## [How to manage memory when using JuMP+Gurobi?](https://discourse.julialang.org/t/how-to-manage-memory-when-using-jump-gurobi/136807)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 10\
**Last updated:** [June 11, 2026, 9:18pm UTC](https://discourse.julialang.org/t/how-to-manage-memory-when-using-jump-gurobi/136807 "2026-06-11T21:18:30Z")

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Observe this usr@usr:~/julia\_projects/uc/Uc$ julia --project=. --threads=1,0 \_ \_ \_ \_(\_)\_ | Documentation: https://docs.julialang.org (\_) | (\_) (\_) | \_ \_ \_| |\_ \_\_ \_ | Type "…

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## [Creating JuMP decision variables more cautiously](https://discourse.julialang.org/t/creating-jump-decision-variables-more-cautiously/137208)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 4\
**Last updated:** [May 21, 2026, 2:52am UTC](https://discourse.julialang.org/t/creating-jump-decision-variables-more-cautiously/137208 "2026-05-21T02:52:31Z")

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I’m studying the Unit Commitment problem which typically has a 24-hour planning horizon. So each generator (if we use the 2-Bin formulation with turn-on decision u and ON/OFF state decision x) will have at least 48 binar…

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## [Gurobi fails to invoke the primal simplex method when doing column generation?](https://discourse.julialang.org/t/gurobi-fails-to-invoke-the-primal-simplex-method-when-doing-column-generation/133675)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 18\
**Last updated:** [April 30, 2026, 9:17pm UTC](https://discourse.julialang.org/t/gurobi-fails-to-invoke-the-primal-simplex-method-when-doing-column-generation/133675 "2026-04-30T21:17:20Z")

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I have a refreshing discovery today, based on my acquaintance Column generation · JuMP wherein, the only thing I changed was the solver (I used Gurobi instead of HiGHS). This is the master LP’s re-solving logging I acq…

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## [JuMP: unused \`@operator\` has critical impact](https://discourse.julialang.org/t/jump-unused-operator-has-critical-impact/136895)

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**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 2\
**Last updated:** [April 27, 2026, 5:45am UTC](https://discourse.julialang.org/t/jump-unused-operator-has-critical-impact/136895 "2026-04-27T05:45:25Z")

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I have some model defined like fake\_fun(a,b) = 0 function my\_model() ... @operator(m, unused\_op, 2, fake\_fun) ... end where both unused\_op and fake\_fun are not used anywhere except on that line. With thi…

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## [Jump, MultiObjectiveAlgorithms - How do manuelly set priorities of objectives](https://discourse.julialang.org/t/jump-multiobjectivealgorithms-how-do-manuelly-set-priorities-of-objectives/136823)

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**Author:** [@Caroline](https://discourse.julialang.org/u/Caroline)\
**Replies:** 2\
**Last updated:** [April 22, 2026, 8:40pm UTC](https://discourse.julialang.org/t/jump-multiobjectivealgorithms-how-do-manuelly-set-priorities-of-objectives/136823 "2026-04-22T20:40:49Z")

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Hi everyone! I’m new to Julia and trying to use it to implement a MILP with multiple objectives. I haven’t been able to find how to set the priorities for the different objectives. Here objective 1 is x+5 and objective 2…

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## [90% of Ipopt run time is spent in Hessian/constraints evaluation, very little time in linear solver. Is it normal?](https://discourse.julialang.org/t/90-of-ipopt-run-time-is-spent-in-hessian-constraints-evaluation-very-little-time-in-linear-solver-is-it-normal/136708)

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**Author:** [@Ceserik](https://discourse.julialang.org/u/Ceserik)\
**Replies:** 11\
**Last updated:** [April 18, 2026, 7:55am UTC](https://discourse.julialang.org/t/90-of-ipopt-run-time-is-spent-in-hessian-constraints-evaluation-very-little-time-in-linear-solver-is-it-normal/136708 "2026-04-18T07:55:51Z")

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Hello, I have been trying to improve my solve time for nonlinear optimal control problem , it is a tool for solving minimum lap time for a race car GitHub - ceserik/SLapSim.jl: Scalable laptime simulator · GitHub. I am…

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## [Bottleneck of JuMP](https://discourse.julialang.org/t/bottleneck-of-jump/136609)

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**Author:** [@ttx002000](https://discourse.julialang.org/u/ttx002000)\
**Replies:** 24\
**Last updated:** [April 15, 2026, 8:38pm UTC](https://discourse.julialang.org/t/bottleneck-of-jump/136609 "2026-04-15T20:38:55Z")

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I am solving a SDP problem using JuMP and the associated MosekTools. The basic pattern is this:\` NQ=9 Nk=9 nred=4 Dmatrix = Vector{Any}(undef, 3) Dmatrix\[1\] = Vector{Any}(undef, NQ) # uuuu channel Dmatr…

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## [Is JuMP.@variable slow when the number gets large?](https://discourse.julialang.org/t/is-jump-variable-slow-when-the-number-gets-large/136430)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 12\
**Last updated:** [April 5, 2026, 12:47am UTC](https://discourse.julialang.org/t/is-jump-variable-slow-when-the-number-gets-large/136430 "2026-04-05T00:47:13Z")

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I have a Unit commitment (24 hours, 5000 scenarios, IEEE118) problem, that has these two lines @time JuMP.@variable(m, pA\[i=\_2(t,T,1), \_0(i,t,S), agi\]) @time JuMP.@variable(m, pf\[i=\_2(t,T,0), \_0(i,t,S), 1:size(F,1)\]) w…

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## [Can I create a null JuMP.VariableRef?](https://discourse.julialang.org/t/can-i-create-a-null-jump-variableref/136492)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 5\
**Last updated:** [April 3, 2026, 1:33am UTC](https://discourse.julialang.org/t/can-i-create-a-null-jump-variableref/136492 "2026-04-03T01:33:50Z")

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I can pre-allocate a JuMP.AffExpr(0.). But can I create a dumb x = JuMP.VariableRef(undef)? Then I can write something like v = JuMP.Containers.@container(\[i=1:3\], x) for i = 1:3 if i !== 3 v\[i\] = JuMP.@var…

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## [MadNLP.jl in JuMP](https://discourse.julialang.org/t/madnlp-jl-in-jump/136380)

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**Author:** [@nico](https://discourse.julialang.org/u/nico)\
**Replies:** 2\
**Last updated:** [March 26, 2026, 8:59am UTC](https://discourse.julialang.org/t/madnlp-jl-in-jump/136380 "2026-03-26T08:59:17Z")

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Hi All, I am trying to change some settings in MadNLP.jl when used via JuMP.jl. I would like to change the barrier strategy from the default monotone to adaptive. I just do not manage to change those settings. Does anyon…

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## [ERROR: MethodError: similar(::JuMP.Containers.DenseAxisArray) is ambiguous](https://discourse.julialang.org/t/error-methoderror-similar-jump-containers-denseaxisarray-is-ambiguous/136359)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 1\
**Last updated:** [March 24, 2026, 7:50pm UTC](https://discourse.julialang.org/t/error-methoderror-similar-jump-containers-denseaxisarray-is-ambiguous/136359 "2026-03-24T19:50:31Z")

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I’m on my Windows laptop. And the GLMakie reports an Error. julia\> f = Figure(); julia\> # do some plots to f, without ERROR here, but next: julia\> f Error showing value of type Figure: SYSTEM (REPL): showing an erro…

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## [\`dual\_objective\_value\` in JuMP.solution\_summary](https://discourse.julialang.org/t/dual-objective-value-in-jump-solution-summary/134556)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 12\
**Last updated:** [March 23, 2026, 1:06am UTC](https://discourse.julialang.org/t/dual-objective-value-in-jump-solution-summary/134556 "2026-03-23T01:06:09Z")

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I have a question: what is the dual\_objective\_value below julia\> JuMP.solution\_summary(model) solution\_summary(; result = 1, verbose = false) ├ solver\_name : Gurobi ├ Termination │ ├ termination\_status : OPTIMA…

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## [Do JuMP Variable ensure contiguous memory to Gurobi?](https://discourse.julialang.org/t/do-jump-variable-ensure-contiguous-memory-to-gurobi/136177)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 7\
**Last updated:** [March 18, 2026, 6:17am UTC](https://discourse.julialang.org/t/do-jump-variable-ensure-contiguous-memory-to-gurobi/136177 "2026-03-18T06:17:38Z")

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The motivation is that I notices Gurobi exposes the 3 APIs. GRBsetdblattrelement GRBsetdblattrarray GRBsetdblattrlist Allegedly, using GRBsetdblattrarray should be the fastest (than using the list counterpart, than us…

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## [MathOptInterface and MultiObjectiveAlgorithms functionality to implement a multiobjective algorithm (AUGMECON)](https://discourse.julialang.org/t/mathoptinterface-and-multiobjectivealgorithms-functionality-to-implement-a-multiobjective-algorithm-augmecon/136243)

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**Author:** [@Josa9321](https://discourse.julialang.org/u/Josa9321)\
**Replies:** 1\
**Last updated:** [March 17, 2026, 8:39pm UTC](https://discourse.julialang.org/t/mathoptinterface-and-multiobjectivealgorithms-functionality-to-implement-a-multiobjective-algorithm-augmecon/136243 "2026-03-17T20:39:48Z")

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Hi. I’m currently working on adapting an AUGMECON implementation in JuMP to use the MultiObjectiveAlgorithms module as its base. As part of this process, I’m adjusting AUGMECON to follow the MOA structure and implementi…

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## [Bridging MTK and JuMP](https://discourse.julialang.org/t/bridging-mtk-and-jump/136148)

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**Author:** [@langestefan](https://discourse.julialang.org/u/langestefan)\
**Replies:** 5\
**Last updated:** [March 12, 2026, 2:19pm UTC](https://discourse.julialang.org/t/bridging-mtk-and-jump/136148 "2026-03-12T14:19:53Z")

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I am doing some basic thermal modelling in MTK, and I want to use the resulting discretized dynamics in a JuMP model. I came up with the following PoC: using Pkg Pkg.activate(".") import ModelingToolkit as MTK using J…

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## [Does AmplNLWriter support most of the functionalities that jump natively provides through MathOptInterface?](https://discourse.julialang.org/t/does-amplnlwriter-support-most-of-the-functionalities-that-jump-natively-provides-through-mathoptinterface/135939)

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**Author:** [@Mihir\_V146](https://discourse.julialang.org/u/Mihir_V146)\
**Replies:** 7\
**Last updated:** [March 6, 2026, 2:00am UTC](https://discourse.julialang.org/t/does-amplnlwriter-support-most-of-the-functionalities-that-jump-natively-provides-through-mathoptinterface/135939 "2026-03-06T02:00:53Z")

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I am trying to decide if I should start making some kind of MathOptInterface for my solver to make jump interface directly with it or should i just use the AmplNLWriter to indirectly talk to jump. The solver I have alrea…

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## [Seeking low rank solution for two PSD matrices via \`SDPLR.jl\` in \`JuMP\`](https://discourse.julialang.org/t/seeking-low-rank-solution-for-two-psd-matrices-via-sdplr-jl-in-jump/135823)

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**Author:** [@Shuvomoy\_Das\_Gupta](https://discourse.julialang.org/u/Shuvomoy_Das_Gupta)\
**Replies:** 9\
**Last updated:** [February 26, 2026, 2:24pm UTC](https://discourse.julialang.org/t/seeking-low-rank-solution-for-two-psd-matrices-via-sdplr-jl-in-jump/135823 "2026-02-26T14:24:46Z")

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I am trying the SDPLR.jl solver in JuMP for finding low-rank solutions to SDPs and it is working quite nicely when the underlying semidefinite optimization problem has only one PSD variable X. How do I apply SDPLR.jl in J…

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## [Get varRefs of whole container](https://discourse.julialang.org/t/get-varrefs-of-whole-container/135726)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 4\
**Last updated:** [February 19, 2026, 7:44pm UTC](https://discourse.julialang.org/t/get-varrefs-of-whole-container/135726 "2026-02-19T19:44:16Z")

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Is there a way to get the variable refs of the whole container? julia\> @variable(model, u\[1:2\]) 2-element Vector{VariableRef}: u\[1\] u\[2\] julia\> variable\_by\_name(model, "u\[2\]") u\[2\] How do I get all u as Vector{Varia…

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## [Why does \`JuMP.set\_objective\_coefficient(m, x, c::Float64)\` have allocations?](https://discourse.julialang.org/t/why-does-jump-set-objective-coefficient-m-x-c-float64-have-allocations/135717)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 7\
**Last updated:** [February 18, 2026, 1:31pm UTC](https://discourse.julialang.org/t/why-does-jump-set-objective-coefficient-m-x-c-float64-have-allocations/135717 "2026-02-18T13:31:43Z")

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I’m very curious here. Where can this API lead to allocations so that it has even more allocations that @objective (in number of allocations, though not in total memory size) when I want to reset the objective function? …

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## [(JuMP) Best way to implement sequential convex (or quadratic) programming](https://discourse.julialang.org/t/jump-best-way-to-implement-sequential-convex-or-quadratic-programming/135669)

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**Author:** [@jackyarndley](https://discourse.julialang.org/u/jackyarndley)\
**Replies:** 4\
**Last updated:** [February 17, 2026, 2:43am UTC](https://discourse.julialang.org/t/jump-best-way-to-implement-sequential-convex-or-quadratic-programming/135669 "2026-02-17T02:43:39Z")

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Hi all, I work with sequential convex programming (SCP) for trajectory optimization, which is where a nonlinear programming problem is approximated by a sequence of convex linearizations. The structure of the problem do…

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