# How to delete zeros from matrix?

**URL:** <https://discourse.julialang.org/t/how-to-delete-zeros-from-matrix/30401>\
**Category:** New to Julia\
**Tags:** question\
**Created:** [October 28, 2019, 1:48pm UTC](https://discourse.julialang.org/t/how-to-delete-zeros-from-matrix/30401 "2019-10-28T13:48:51Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Biljana\_Radovanovic](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/biljana_radovanovic/32/11026_2.png) [@Biljana\_Radovanovic](https://discourse.julialang.org/u/Biljana_Radovanovic)\
**Post date:** [October 28, 2019, 1:48pm UTC](https://discourse.julialang.org/t/how-to-delete-zeros-from-matrix/30401/1 "2019-10-28T13:48:51Z")

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How to delete zeros from matrix delete and delete! does not work?

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**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [October 28, 2019, 1:49pm UTC](https://discourse.julialang.org/t/how-to-delete-zeros-from-matrix/30401/2 "2019-10-28T13:49:58Z")

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Let’s say you have:

```julia
[1 0 1;
 0 1 1;
 0 0 1]

```

What do you want the result of “delete zeros” to be?

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**Author:** ![spaceLem](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/spacelem/32/217628_2.png) [@spaceLem](https://discourse.julialang.org/u/spaceLem)\
**Post date:** [October 28, 2019, 4:08pm UTC](https://discourse.julialang.org/t/how-to-delete-zeros-from-matrix/30401/3 "2019-10-28T16:08:46Z")

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Just in case you’re talking about sparse matrices, then the functions you’re looking for are `dropzeros()` and `dropzeros!()`.

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<div class="post-metadata">

**Author:** ![Biljana\_Radovanovic](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/biljana_radovanovic/32/11026_2.png) [@Biljana\_Radovanovic](https://discourse.julialang.org/u/Biljana_Radovanovic)\
**Post date:** [October 28, 2019, 8:24pm UTC](https://discourse.julialang.org/t/how-to-delete-zeros-from-matrix/30401/4 "2019-10-28T20:24:06Z")

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in what packgate is because it doesn;t work?

пон, 28. окт 2019. у 17:13 Jamie via JuliaLang [julialang@discoursemail.com](mailto:julialang@discoursemail.com) је написао/ла:

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**Author:** ![mbauman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mbauman/32/31082_2.png) [@mbauman](https://discourse.julialang.org/u/mbauman)\
**Post date:** [October 28, 2019, 8:29pm UTC](https://discourse.julialang.org/t/how-to-delete-zeros-from-matrix/30401/5 "2019-10-28T20:29:59Z")

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If `dropzeros` doesn’t work then it won’t be applicable to your case — it only applies to [SparseArrays](https://docs.julialang.org/en/v1/stdlib/SparseArrays/).

Probably what you want is something like `filter(!iszero, A)`, which will return all nonzero elements as a vector… but you could also reasonably want all rows without any nonzeros, or all rows that aren’t all nonzero, or …, or …

We need a bit more to go on 🙂