# Arpack is broken?
**URL:** https://discourse.julialang.org/t/arpack-is-broken/94758
**Category:** Performance
**Tags:** package
**Created:** [February 17, 2023, 12:29am UTC](https://discourse.julialang.org/t/arpack-is-broken/94758 "2023-02-17T00:29:05Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)
#### Post date: [February 17, 2023, 12:29am UTC](https://discourse.julialang.org/t/arpack-is-broken/94758/1 "2023-02-17T00:29:05Z")
Hi all. sorry to bother you guys.
I wrote a code a couple of years back that used Arpack in julia. I am updating it but I can´t run it.
In my notes for it I have this:
- Arpacy\_jll must be the newer version. The older one has problems with large eigenvalues problem.
Pkg.add(Pkg.PackageSpec(;name=“Arpack\_jll”, version=“3.8”));
- The above library (as of today) requires the old version of Arpack as it is more stable
Pkg.add(Pkg.PackageSpec(;name=“Arpack”, version=“0.5.0”));
When I run it I get this error.
I wonder if there is any work around.
```julia
ERROR: ┌ Error: XYAUPD_Exception: Maximum number of iterations taken. All possible eigenvalues of OP has been found.
│ IPARAM(5) returns the number of wanted converged Ritz values.
│ info = 1
└ @ Arpack ~/.julia/packages/Arpack/FCvNd/src/libarpack.jl:47
Stacktrace:
[1] aupd_wrapper(T::Type, matvecA!::Arpack.var"#17#27"{SparseMatrixCSC{Float64, Int64}}, matvecB::Arpack.var"#13#23", solveSI::Arpack.var"#18#28", n::Int64, sym::Bool, cmplx::Bool, bmat::String, nev::Int64, ncv::Int64, which::String, tol::Float64, maxiter::Int64, mode::Int64, v0::Vector{Float64}, check::Int64)
@ Arpack ~/.julia/packages/Arpack/FCvNd/src/libarpack.jl:141
[2] _eigs(A::SparseMatrixCSC{Float64, Int64}, B::SparseMatrixCSC{Float64, Int64}; nev::Int64, ncv::Int64, which::Symbol, tol::Float64, maxiter::Int64, sigma::Float64, v0::Vector{Float64}, ritzvec::Bool, explicittransform::Symbol, check::Int64)
@ Arpack ~/.julia/packages/Arpack/FCvNd/src/Arpack.jl:240
[3] #eigs#5
@ ~/.julia/packages/Arpack/FCvNd/src/Arpack.jl:53 [inlined]
[4] kwcall(::NamedTuple{(:nev, :sigma, :tol, :ncv, :maxiter, :which), Tuple{Int64, Float64, Float64, Int64, Int64, Symbol}}, ::typeof(eigs), A::SparseMatrixCSC{Float64, Int64}, B::SparseMatrixCSC{Float64, Int64})
@ Arpack ~/.julia/packages/Arpack/FCvNd/src/Arpack.jl:53
[5] Rayleigh_Forwardsp(Nsolid::Int64, vsv::Vector{Float64}, vpv::Vector{Float64}, rhov::Vector{Float64}, f::Vector{Float64}, hsolid::Vector{Float64}, Nmodes::Int64, Nfluid::Int64, vpfv::Matrix{Float64}, rhofv::Matrix{Float64}, hfv::Matrix{Float64}, qsv::Vector{Float64})
@ Main ~/Documents/JULIA_UCM/SeitComp-1D_ForTesting2/src/seis/SW_Disp.jl:499
[6] SW_Disp(Model::Matrix{Float64}, h_index::Int64, Obs_T::StepRange{Int64, Int64}, Nmodes::Int64, Anisotropy::Int64)
@ Main ~/Documents/JULIA_UCM/SeitComp-1D_ForTesting2/src/seis/SW_Disp.jl:42
[7] top-level scope
@ REPL[27]:1
```
---
### Author:  [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)
#### Post date: [February 17, 2023, 12:54am UTC](https://discourse.julialang.org/t/arpack-is-broken/94758/2 "2023-02-17T00:54:52Z")
Is, Arpack 0.5.4 is indeed broken. [eigs() doesn't work in my computer, but works in another one. (Arpack 0.5.4) · Issue #147 · JuliaLinearAlgebra/Arpack.jl · GitHub](https://github.com/JuliaLinearAlgebra/Arpack.jl/issues/147). I would suggest to use 0.5.3.
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### Author:  [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)
#### Post date: [February 19, 2023, 6:33pm UTC](https://discourse.julialang.org/t/arpack-is-broken/94758/3 "2023-02-19T18:33:34Z")
Thanks for the info. Do you happen to have 0.5.0? It was the last version that worked for me ☹
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### Author:  [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)
#### Post date: [February 19, 2023, 7:29pm UTC](https://discourse.julialang.org/t/arpack-is-broken/94758/4 "2023-02-19T19:29:35Z")
0.5.3 works for me. If you set compat to `Arpack = "=0.5.0"` you will get that.
>