# How to create a (n-1) dimensional view of a n dimensional array in a general way?

**URL:** <https://discourse.julialang.org/t/how-to-create-a-n-1-dimensional-view-of-a-n-dimensional-array-in-a-general-way/55597>\
**Category:** New to Julia\
**Created:** [February 19, 2021, 2:37am UTC](https://discourse.julialang.org/t/how-to-create-a-n-1-dimensional-view-of-a-n-dimensional-array-in-a-general-way/55597 "2021-02-19T02:37:12Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![liuyxpp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/liuyxpp/32/9870_2.png) [@liuyxpp](https://discourse.julialang.org/u/liuyxpp)\
**Post date:** [February 19, 2021, 2:37am UTC](https://discourse.julialang.org/t/how-to-create-a-n-1-dimensional-view-of-a-n-dimensional-array-in-a-general-way/55597/1 "2021-02-19T02:37:12Z")

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For the n-dimensional array, I can do it separately

```julia
A[:, 1] # for 2D
A[:, :, 1] # for 3D
A[:, :, :, 1] # for 4D

```

but how can I do it generally if n is not known in advance? i.e. the number of colons is unknown.

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**Author:** ![marius311](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/marius311/32/3953_2.png) [@marius311](https://discourse.julialang.org/u/marius311)\
**Post date:** [February 19, 2021, 2:40am UTC](https://discourse.julialang.org/t/how-to-create-a-n-1-dimensional-view-of-a-n-dimensional-array-in-a-general-way/55597/2 "2021-02-19T02:40:19Z")

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```julia
using Base.Iterators
A[repeated(:,ndims(A)-1)..., 1]

```

or with [EllipsisNotation.jl](https://github.com/ChrisRackauckas/EllipsisNotation.jl):

```julia
A[.., 1]

```

---

<div class="post-metadata">

**Author:** ![liuyxpp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/liuyxpp/32/9870_2.png) [@liuyxpp](https://discourse.julialang.org/u/liuyxpp)\
**Post date:** [February 19, 2021, 2:50am UTC](https://discourse.julialang.org/t/how-to-create-a-n-1-dimensional-view-of-a-n-dimensional-array-in-a-general-way/55597/3 "2021-02-19T02:50:45Z")

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Ah, thanks! Follow your suggestions, I also come up with another solution

```julia
A[fill(:, ndimis(A)-1)..., 1]

```