# \#dual

**URL:** https://discourse.julialang.org/tag/dual/1007.md

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## [JuMP.shadow\_price conveys a misconception?](https://discourse.julialang.org/t/jump-shadow-price-conveys-a-misconception/127503)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 5\
**Last updated:** [June 11, 2025, 7:44am UTC](https://discourse.julialang.org/t/jump-shadow-price-conveys-a-misconception/127503 "2025-06-11T07:44:19Z")

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In constraint optimization, the shadow price is the change, per infinitesimal unit of the constraint, in the optimal value of the objective function, obtained by relaxing the constraint. This is the wikipedia definiti…

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## [Most efficient way of retrieving dual solutions iteratively](https://discourse.julialang.org/t/most-efficient-way-of-retrieving-dual-solutions-iteratively/122790)

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**Author:** [@BMI\_OR](https://discourse.julialang.org/u/BMI_OR)\
**Replies:** 1\
**Last updated:** [November 18, 2024, 9:38pm UTC](https://discourse.julialang.org/t/most-efficient-way-of-retrieving-dual-solutions-iteratively/122790 "2024-11-18T21:38:03Z")

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I have implemented an algorithm where at each iteration I need to solve an optimization model and retrieve its dual solution. Currently, I am using dual.() to get the solution, and I am seeing that this function is also …

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## [Extreme ray values unbounded LP JuMP](https://discourse.julialang.org/t/extreme-ray-values-unbounded-lp-jump/102686)

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**Author:** [@bcoulier](https://discourse.julialang.org/u/bcoulier)\
**Replies:** 5\
**Last updated:** [August 11, 2023, 12:56pm UTC](https://discourse.julialang.org/t/extreme-ray-values-unbounded-lp-jump/102686 "2023-08-11T12:56:39Z")

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I’m currently dealing with an LP problem where the solution to the primal turns out to be infeasible, leading to an unbounded dual. In order to create a feasibility cut, I’m aiming to acquire the extreme ray values from …

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## [Are computations with Dual numbers twice as slow as non Duals?](https://discourse.julialang.org/t/are-computations-with-dual-numbers-twice-as-slow-as-non-duals/92502)

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**Author:** [@nrontsis](https://discourse.julialang.org/u/nrontsis)\
**Replies:** 2\
**Last updated:** [January 4, 2023, 2:39pm UTC](https://discourse.julialang.org/t/are-computations-with-dual-numbers-twice-as-slow-as-non-duals/92502 "2023-01-04T14:39:08Z")

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After reading this I got the impression that computations with dual numbers are typically expected to be twice as slow as non-duals. The reasoning was that both the normal and dual computations have to calculated at each…

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## [ForwardDiff Dual Type problem with GLM](https://discourse.julialang.org/t/forwarddiff-dual-type-problem-with-glm/85045)

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**Author:** [@YangkeunYun](https://discourse.julialang.org/u/YangkeunYun)\
**Replies:** 2\
**Last updated:** [July 31, 2022, 2:50pm UTC](https://discourse.julialang.org/t/forwarddiff-dual-type-problem-with-glm/85045 "2022-07-31T14:50:57Z")

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Hi, I am working on ForwardDiff package to implement some optimizations. The core problem comes from Dual type (made by autodiff of ForwardDiff) and GLM package. I’ve seen other posts related to the issues with FowardD…

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## [Correct Way to Compose ReverseDiff and ForwardDiff](https://discourse.julialang.org/t/correct-way-to-compose-reversediff-and-forwarddiff/83708)

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**Author:** [@RS-Coop](https://discourse.julialang.org/u/RS-Coop)\
**Replies:** 8\
**Last updated:** [July 4, 2022, 3:22pm UTC](https://discourse.julialang.org/t/correct-way-to-compose-reversediff-and-forwarddiff/83708 "2022-07-04T15:22:45Z")

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I am trying to use ReverseDiff.jl and ForwardDiff.jl as a mixed mode AD approach to computing a Hessian vector product. I am using the following function: import ForwardDiff as fdiff import ReverseDiff as rdiff functio…

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## [Early Stopping Using Float Cutoff on Dual](https://discourse.julialang.org/t/early-stopping-using-float-cutoff-on-dual/79516)

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**Author:** [@chelseas](https://discourse.julialang.org/u/chelseas)\
**Replies:** 2\
**Last updated:** [April 15, 2022, 11:27pm UTC](https://discourse.julialang.org/t/early-stopping-using-float-cutoff-on-dual/79516 "2022-04-15T23:27:31Z")

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I cannot figure out how to do the following. I would like for JuMP to stop once the dual bound (lower bound for minimization) is above some value. OR similarly, once the dual bound (upper bound for maximization) is belo…