# Where is \`eigs()\` in Julia 1.0 version?

**URL:** <https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743>\
**Category:** General Usage\
**Tags:** linearalgebra\
**Created:** [May 29, 2019, 5:51pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743 "2019-05-29T17:51:33Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![Carol](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/carol/32/8140_2.png) [@Carol](https://discourse.julialang.org/u/Carol)\
**Post date:** [May 29, 2019, 5:51pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/1 "2019-05-29T17:51:33Z")

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Hi,

I want to use `eigs()` to get the largest eigenvalue of a huge dense symmetric matrix.(50k by 50k)  
I can find `eigs()` in the documentation of [Julia 0.6.4](https://docs.julialang.org/en/v0.6/stdlib/linalg/#Base.LinAlg.eigs-Tuple%7BAny%7D), but cannot find it in Julia 1.0.4 or 1.0.1.

Could you please tell me how I can use `eigs()` in v1.0 Julia?

Thanks

* * *

The reason why I want to use `eigs()` is that the BLAS function `LAPACK.syevr!` implemented in `eigvals!()` is too slow for me. It took 1.5 hours for a 50k by 50k symmetric matirx.

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**Author:** ![tkoolen](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tkoolen/32/1603_2.png) [@tkoolen](https://discourse.julialang.org/u/tkoolen)\
**Post date:** [May 29, 2019, 5:55pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/2 "2019-05-29T17:55:57Z")

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From the other topic:

> [@Special method for finding eigenvalues of a large sparse symmetric matrix?](https://discourse.julialang.org/t/special-method-for-finding-eigenvalues-of-a-large-sparse-symmetric-matrix/9621/18):
>
> `eigs` has moved to Arpack.jl. Documentation is here: [Home · Arpack.jl](https://julialinearalgebra.github.io/Arpack.jl/stable/).

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**Author:** ![JeffreySarnoff](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jeffreysarnoff/32/1980_2.png) [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Post date:** [May 29, 2019, 5:56pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/3 "2019-05-29T17:56:42Z")

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do this, then these functions [Linear Algebra · The Julia Language](https://docs.julialang.org/en/v1.2-dev/stdlib/LinearAlgebra/#) are available

```julia
using LinearAlgebra

```

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<div class="post-metadata">

**Author:** ![Carol](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/carol/32/8140_2.png) [@Carol](https://discourse.julialang.org/u/Carol)\
**Post date:** [May 29, 2019, 5:59pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/4 "2019-05-29T17:59:00Z")

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Hi,thanks for your reply. But there is no `eigs()`.

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<div class="post-metadata">

**Author:** ![JeffreySarnoff](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jeffreysarnoff/32/1980_2.png) [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Post date:** [May 29, 2019, 5:59pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/5 "2019-05-29T17:59:39Z")

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there is `eigmax` and `eigvals`

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<div class="post-metadata">

**Author:** ![Carol](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/carol/32/8140_2.png) [@Carol](https://discourse.julialang.org/u/Carol)\
**Post date:** [May 29, 2019, 6:01pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/6 "2019-05-29T18:01:01Z")

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Yes I know. They are using BLAS function `LAPACK.syevr!`, which is slow for large symmetric matrix.

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<div class="post-metadata">

**Author:** ![JeffreySarnoff](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jeffreysarnoff/32/1980_2.png) [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Post date:** [May 29, 2019, 6:01pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/7 "2019-05-29T18:01:59Z")

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> [@tkoolen](#):
>
> `eigs` has moved to Arpack.jl. Documentation is here: [Home · Arpack.jl](https://julialinearalgebra.github.io/Arpack.jl/stable/).

that would be your function

(if you are unfamiliar with the new package manager…)

```julia
julia> using Pkg; Pkg.add("Arpack");

```

then

```julia
using Arpack

```

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<div class="post-metadata">

**Author:** ![Carol](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/carol/32/8140_2.png) [@Carol](https://discourse.julialang.org/u/Carol)\
**Post date:** [May 29, 2019, 6:19pm UTC](https://discourse.julialang.org/t/where-is-eigs-in-julia-1-0-version/24743/8 "2019-05-29T18:19:31Z")

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Thanks! it works!