# How to do sparse row vector\*matrix?
**URL:** https://discourse.julialang.org/t/how-to-do-sparse-row-vector-matrix/121166
**Category:** New to Julia
**Created:** [October 10, 2024, 9:01pm UTC](https://discourse.julialang.org/t/how-to-do-sparse-row-vector-matrix/121166 "2024-10-10T21:01:21Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@happyxie](https://discourse.julialang.org/u/happyxie)
#### Post date: [October 10, 2024, 9:01pm UTC](https://discourse.julialang.org/t/how-to-do-sparse-row-vector-matrix/121166/1 "2024-10-10T21:01:21Z")
I am trying to do a row vector times a matrix but it give an adjoint type instead of a row vector? should I do (A’A[1,:])'? I need the results to be a vector so I can continue other calculation.
Thanks.
A=sparse([1 2;3 4])
A[1,:]'A
#1×2 adjoint(::SparseVector{Int64, Int64}) with eltype Int64
---
### Author:  [@stevengj](https://discourse.julialang.org/u/stevengj)
#### Post date: [October 10, 2024, 9:25pm UTC](https://discourse.julialang.org/t/how-to-do-sparse-row-vector-matrix/121166/2 "2024-10-10T21:25:39Z")
> [@happyxie](#):
>
> adjoint type instead of a row vector?
That is a row vector. [https://www.youtube.com/watch?v=C2RO34b\_oPM](https://www.youtube.com/watch?v=C2RO34b_oPM)
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### Author:  [@happyxie](https://discourse.julialang.org/u/happyxie)
#### Post date: [October 10, 2024, 9:37pm UTC](https://discourse.julialang.org/t/how-to-do-sparse-row-vector-matrix/121166/3 "2024-10-10T21:37:00Z")
Thanks. But I just did a type conversion for it like:
sparsevec(A[1,:]'A)
This solved my problem.
---
### Author:  [@mikmoore](https://discourse.julialang.org/u/mikmoore)
#### Post date: [October 11, 2024, 1:43pm UTC](https://discourse.julialang.org/t/how-to-do-sparse-row-vector-matrix/121166/4 "2024-10-11T13:43:41Z")
A little more direct (and performant) is either of
```julia-repl
julia> (A[1,:]' * A)'
2-element SparseVector{Int64, Int64} with 2 stored entries:
[1] = 7
[2] = 10
julia> A' * A[1,:]
2-element SparseVector{Int64, Int64} with 2 stored entries:
[1] = 7
[2] = 10
```
For real numbers this is fine, but if your numbers are complex then you should be careful about the conjugation of the result.