# Problems using solvers from Iterativesolvers.jl in DifferentialEquations.jl

**URL:** <https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935>\
**Category:** General Usage\
**Tags:** diffeq, sciml\
**Created:** [April 24, 2021, 4:12pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935 "2021-04-24T16:12:44Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![amael](https://avatars.discourse-cdn.com/v4/letter/a/e95f7d/32.png) [@amael](https://discourse.julialang.org/u/amael)\
**Post date:** [April 24, 2021, 4:12pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935/1 "2021-04-24T16:12:45Z")

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Hi,

Trying the `LinSolveIterativeSolvers` API of DifferentialEquations.jl to use the linear solvers from IterativeSolvers.jl always lead to some errors. I’m using julia 1.6.

First the API only works for the gmres solver but it leads to a specific error:  
`no method matching eps(::Type{ComplexF64})`

For the other solvers (cg, bicgstabl, minres and chebyshev), the API is wrong, for instance the bicgstabl error is:  
`bicgstabl_iterator!(::Any, ::Any, ::Any, ::Int64; Pl, max_mv_products, abstol, reltol, initial_zero) at /Users/amael/.julia/packages/IterativeSolvers/TpeDx/src/bicgstabl.jl:27 got unsupported keyword arguments "initially_zero", "restart", "maxiter", "Pr"`.

Best,  
Amael

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [April 29, 2021, 3:29pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935/2 "2021-04-29T15:29:03Z")

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Yeah the IterativeSolver API drifted and needs a few more tests in DiffEqBase. I believe you opened an issue and we can follow up there.

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**Author:** ![ziolai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ziolai/32/23422_2.png) [@ziolai](https://discourse.julialang.org/u/ziolai)\
**Post date:** [August 15, 2022, 5:02pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935/3 "2022-08-15T17:02:54Z")

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Has this solved? Is resorting to petsc.jl an option here? Thx.

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [August 15, 2022, 6:29pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935/4 "2022-08-15T18:29:27Z")

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This was solved a long time ago. See the tutorial [Solving Large Stiff Equations · DifferentialEquations.jl](https://diffeq.sciml.ai/stable/tutorials/advanced_ode_example/) for some details.

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**Author:** ![ziolai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ziolai/32/23422_2.png) [@ziolai](https://discourse.julialang.org/u/ziolai)\
**Post date:** [August 15, 2022, 7:12pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935/5 "2022-08-15T19:12:40Z")

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Apologies. My bad. I am looking for a iterative linear solver able to solve complex valued linear systems.

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<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [August 15, 2022, 7:21pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935/6 "2022-08-15T19:21:25Z")

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Did the KrylovJL\_GMRES one shown in the tutorial not work?

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**Author:** ![ziolai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ziolai/32/23422_2.png) [@ziolai](https://discourse.julialang.org/u/ziolai)\
**Post date:** [August 15, 2022, 7:22pm UTC](https://discourse.julialang.org/t/problems-using-solvers-from-iterativesolvers-jl-in-differentialequations-jl/59935/7 "2022-08-15T19:22:38Z")

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Will check and get back to you. Thx.