# KrylovKit, syntax issue

**URL:** <https://discourse.julialang.org/t/krylovkit-syntax-issue/110359>\
**Category:** General Usage\
**Tags:** matrices, eigenvalues\
**Created:** [February 17, 2024, 10:02pm UTC](https://discourse.julialang.org/t/krylovkit-syntax-issue/110359 "2024-02-17T22:02:36Z")\
**Posts on this page:** 1\
**Showing post:** 16

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**Author:** ![Enlil50](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/enlil50/32/206539_2.png) [@Enlil50](https://discourse.julialang.org/u/Enlil50)\
**Post date:** [February 19, 2024, 4:02pm UTC](https://discourse.julialang.org/t/krylovkit-syntax-issue/110359/16 "2024-02-19T16:02:45Z")

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Following the issue in [MKL package wrong results - #3 by Enlil50](https://discourse.julialang.org/t/mkl-package-wrong-results/110405/3) it seems that wrong result were brought upon little (non)zeros of order 10^-16 roaming around the matrix. Whereas for dense matrices I know 2 methods for ensuring symmetricity:

1. A\_sym = 0.5\*(A + A’)
2. A\_sym = Symmetric(A) #this is just a view of the upper triangular section

For sparse matrix I can use just the first one. It seems that it doesn’t change much. just to approach the issue in a different way: is there something which suppresses numbers under a certain tolerance or threshold in a given sparse matrix ,matrix or array? I would like to try it first.

P.S: i expect that in sparse matrix the zeros are treated just like sparse matrix zeros: they should not be considered in linear algebra operations and such. I don’t need to reallocate the vectors, but it could even give me a little boost.

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