# Expand matrix from n x n to n+1 x n+1

**URL:** <https://discourse.julialang.org/t/expand-matrix-from-n-x-n-to-n-1-x-n-1/44365>\
**Category:** Performance\
**Created:** [August 5, 2020, 8:46pm UTC](https://discourse.julialang.org/t/expand-matrix-from-n-x-n-to-n-1-x-n-1/44365 "2020-08-05T20:46:03Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![mleprovost](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mleprovost/32/7166_2.png) [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Post date:** [August 5, 2020, 8:46pm UTC](https://discourse.julialang.org/t/expand-matrix-from-n-x-n-to-n-1-x-n-1/44365/1 "2020-08-05T20:46:03Z")

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Hello,

Is there a convenient function to augment in-place a matrix `A` from n \times n to n+1 \times n+1.

We can always do `A = hcat(vcat(A, zeros(1, size(A,1))), zeros(size(A,1)+1,1))`

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**Author:** ![tomerarnon](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomerarnon/32/3170_2.png) [@tomerarnon](https://discourse.julialang.org/u/tomerarnon)\
**Post date:** [August 5, 2020, 9:17pm UTC](https://discourse.julialang.org/t/expand-matrix-from-n-x-n-to-n-1-x-n-1/44365/2 "2020-08-05T21:17:54Z")

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As far as I know, there is no way to resize matrices in place. You can, however, do

```julia
n, m = size(A)

[A zeros(n);
zeros(m+1)']

```

which lowers to `hvcat`.

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<div class="post-metadata">

**Author:** ![mleprovost](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mleprovost/32/7166_2.png) [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Post date:** [August 5, 2020, 9:26pm UTC](https://discourse.julialang.org/t/expand-matrix-from-n-x-n-to-n-1-x-n-1/44365/3 "2020-08-05T21:26:25Z")

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Thank you for your answer