# What the...? eigs GEP eigenvectors no longer mass-normalized?

**URL:** <https://discourse.julialang.org/t/what-the-eigs-gep-eigenvectors-no-longer-mass-normalized/61667>\
**Category:** General Usage\
**Created:** [May 23, 2021, 3:21am UTC](https://discourse.julialang.org/t/what-the-eigs-gep-eigenvectors-no-longer-mass-normalized/61667 "2021-05-23T03:21:21Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 23, 2021, 3:21am UTC](https://discourse.julialang.org/t/what-the-eigs-gep-eigenvectors-no-longer-mass-normalized/61667/1 "2021-05-23T03:21:22Z")

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What the…? eigs GEP eigenvectors no longer mass-normalized? A nasty bit of surprise. Broke a lot of my code.

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**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [May 23, 2021, 3:42am UTC](https://discourse.julialang.org/t/what-the-eigs-gep-eigenvectors-no-longer-mass-normalized/61667/2 "2021-05-23T03:42:57Z")

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_Metacomment:_ Do we need to update the [manual](https://docs.julialang.org/en/v1/manual/faq/#The-two-uses-of-the-...-operator:-slurping-and-splatting)?  
_Many newcomers to Julia find the use of `...` operator confusing. Part of what makes the `...` operator confusing is that it means two different things depending on context._. 😉

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**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 23, 2021, 2:20pm UTC](https://discourse.julialang.org/t/what-the-eigs-gep-eigenvectors-no-longer-mass-normalized/61667/3 "2021-05-23T14:20:56Z")

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I think this is a clear case of splatting. 😉

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**Author:** ![PetrKryslUCSD](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/petrkryslucsd/32/215825_2.png) [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Post date:** [May 23, 2021, 5:17pm UTC](https://discourse.julialang.org/t/what-the-eigs-gep-eigenvectors-no-longer-mass-normalized/61667/4 "2021-05-23T17:17:34Z")

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Filed an issue: [https://github.com/JuliaLinearAlgebra/Arpack.jl/issues/130](https://github.com/JuliaLinearAlgebra/Arpack.jl/issues/130)