# Infeasibility Testing

**URL:** <https://discourse.julialang.org/t/infeasibility-testing/3910>\
**Category:** Optimization (Mathematical)\
**Created:** [May 24, 2017, 1:22pm UTC](https://discourse.julialang.org/t/infeasibility-testing/3910 "2017-05-24T13:22:58Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![gopal2017](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gopal2017/32/31747_2.png) [@gopal2017](https://discourse.julialang.org/u/gopal2017)\
**Post date:** [May 24, 2017, 1:22pm UTC](https://discourse.julialang.org/t/infeasibility-testing/3910/1 "2017-05-24T13:22:58Z")

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In CPLEX we have option to detect conflicting equations and/ check infeasibility of the model,if any. I am using Clp solver. Is there any option to do aforementioned task?

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**Author:** ![ExpandingMan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/expandingman/32/866_2.png) [@ExpandingMan](https://discourse.julialang.org/u/ExpandingMan)\
**Post date:** [May 24, 2017, 1:42pm UTC](https://discourse.julialang.org/t/infeasibility-testing/3910/2 "2017-05-24T13:42:30Z")

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As far as I know this functionality is usually wrapped by the core C wrapper for each optimization program. Therefore, if the functionality exists I’d think you’d be able to find it in [CPLEX.jl](https://github.com/JuliaOpt/CPLEX.jl). The function call to it probably very closely resembles the function call in the original C API.

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**Author:** ![gopal2017](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gopal2017/32/31747_2.png) [@gopal2017](https://discourse.julialang.org/u/gopal2017)\
**Post date:** [May 24, 2017, 6:36pm UTC](https://discourse.julialang.org/t/infeasibility-testing/3910/3 "2017-05-24T18:36:53Z")

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Well, CPLEX.jl is suitable for CPLEX Solver.Is there any provision in Clp solver to detect causes of infeasibility? Please let me know.

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**Author:** ![ExpandingMan](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/expandingman/32/866_2.png) [@ExpandingMan](https://discourse.julialang.org/u/ExpandingMan)\
**Post date:** [May 24, 2017, 6:47pm UTC](https://discourse.julialang.org/t/infeasibility-testing/3910/4 "2017-05-24T18:47:07Z")

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Sorry, I thought you meant you were using CPLEX. Well, the same thing applies, `Clp.jl` is probably a low-level wrapper of the `Clp` library, so you will have to check the Clp documentation. Apparently Clp recommends you build doxygen, which is rather a pain especially if you are not using the source code, which you probably aren’t, so they have rather lousy documentation. Perhaps someone who is familiar with Clp will chime in.

Looking [here](https://github.com/JuliaOpt/Clp.jl/blob/master/src/ClpCInterface.jl) it seems there are several feasability related functions. You may have to dig through Clp a bit to figure out how best to call them.

For what it’s worth, I’m fairly confident that [GLPK](https://github.com/JuliaOpt/GLPK.jl) is the most widely used and supported open source solver. Figuring out these sorts of things would probably be easier using GLPK.