# Convert n number of 1\*1 matrices to one n\*1 vector

**URL:** <https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182>\
**Category:** General Usage\
**Created:** [August 11, 2021, 6:37am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182 "2021-08-11T06:37:32Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![Chaitanya](https://avatars.discourse-cdn.com/v4/letter/c/848f3c/32.png) [@Chaitanya](https://discourse.julialang.org/u/Chaitanya)\
**Post date:** [August 11, 2021, 6:37am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/1 "2021-08-11T06:37:32Z")

</div>

k=collect(0:0.1:1)

# u is a neural network.

pred=(u.(k))

11-element Vector{Matrix{Float64}}:  
[-0.48909483506995793]  
[-0.46596887211781113]  
[-0.44329630895872524]  
[-0.4211157735999599]  
[-0.39946203623807897]  
[-0.37836588996089027]  
[-0.3578540892654915]  
[-0.3379493434394113]  
[-0.3186703608096747]  
[-0.30003193904325304]  
[-0.28204509608735767]

I want the values to be a single vector. Please help

---

<div class="post-metadata">

**Author:** ![jling](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jling/32/212909_2.png) [@jling](https://discourse.julialang.org/u/jling)\
**Post date:** [August 11, 2021, 6:40am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/2 "2021-08-11T06:40:18Z")

</div>

```julia
mapreduce(vec, vcat, pred)

```

---

<div class="post-metadata">

**Author:** ![genkuroki](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/genkuroki/32/18030_2.png) [@genkuroki](https://discourse.julialang.org/u/genkuroki)\
**Post date:** [August 11, 2021, 7:04am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/3 "2021-08-11T07:04:19Z")

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```julia
v = getindex.(pred, 1, 1)

```

---

<div class="post-metadata">

**Author:** ![jling](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jling/32/212909_2.png) [@jling](https://discourse.julialang.org/u/jling)\
**Post date:** [August 11, 2021, 8:04am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/4 "2021-08-11T08:04:55Z")

</div>

ah, yes

```julia
only.(pred)

```

---

<div class="post-metadata">

**Author:** ![pfitzseb](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pfitzseb/32/45566_2.png) [@pfitzseb](https://discourse.julialang.org/u/pfitzseb)\
**Post date:** [August 11, 2021, 8:40am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/5 "2021-08-11T08:40:31Z")

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Or `first.(pred)` if you want this to work on all 1.x Julia versions.

---

<div class="post-metadata">

**Author:** ![Chaitanya](https://avatars.discourse-cdn.com/v4/letter/c/848f3c/32.png) [@Chaitanya](https://discourse.julialang.org/u/Chaitanya)\
**Post date:** [August 11, 2021, 11:01am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/6 "2021-08-11T11:01:12Z")

</div>

Thank you, everyone

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<div class="post-metadata">

**Author:** ![gustaphe](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gustaphe/32/18174_2.png) [@gustaphe](https://discourse.julialang.org/u/gustaphe)\
**Post date:** [August 11, 2021, 11:49am UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/7 "2021-08-11T11:49:08Z")

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You don’t (and in fact _rarely_) need the `collect` step.

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<div class="post-metadata">

**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:** [August 11, 2021, 1:30pm UTC](https://discourse.julialang.org/t/convert-n-number-of-1-1-matrices-to-one-n-1-vector/66182/8 "2021-08-11T13:30:41Z")

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Using splatting:

```julia
vec(vcat(pred...))

```