# New syntax for Ac\_mul\_B!

**URL:** https://discourse.julialang.org/t/new-syntax-for-ac-mul-b/17126
**Category:** New to Julia
**Tags:** linearalgebra
**Created:** [November 3, 2018, 9:44pm UTC](https://discourse.julialang.org/t/new-syntax-for-ac-mul-b/17126 "2018-11-03T21:44:09Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![rveltz](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rveltz/32/2707_2.png) [@rveltz](https://discourse.julialang.org/u/rveltz)
#### Post date: [November 3, 2018, 9:44pm UTC](https://discourse.julialang.org/t/new-syntax-for-ac-mul-b/17126/1 "2018-11-03T21:44:09Z")

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His

I am trying to update an old code to Julia 1.0. I have some troubles finding the new way of doing

```julia
Ac_mul_B!(h, V, w)
h = Ac_mul_B(V, w)

```

Can someone help me please?

Thank you,

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<div class="post-metadata">

### Author: ![fredrikekre](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fredrikekre/32/1688_2.png) [@fredrikekre](https://discourse.julialang.org/u/fredrikekre)
#### Post date: [November 3, 2018, 9:59pm UTC](https://discourse.julialang.org/t/new-syntax-for-ac-mul-b/17126/2 "2018-11-03T21:59:51Z")

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```julia
mul!(h, V', w) 
h = V' * w

```

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<div class="post-metadata">

### Author: ![rveltz](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rveltz/32/2707_2.png) [@rveltz](https://discourse.julialang.org/u/rveltz)
#### Post date: [November 3, 2018, 10:06pm UTC](https://discourse.julialang.org/t/new-syntax-for-ac-mul-b/17126/3 "2018-11-03T22:06:53Z")

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Thanks!!

I have also `A_mul_B!(AV.curr, A, V.curr)`…

Where can I find these translations so I don’t bother too much?

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### Author: ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)
#### Post date: [November 3, 2018, 10:10pm UTC](https://discourse.julialang.org/t/new-syntax-for-ac-mul-b/17126/4 "2018-11-03T22:10:41Z")

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You can use 0.7 - it has the same features as 1.0, but shows deprecations.

> [@PSA: use Julia 0.7 if you are upgrading](https://discourse.julialang.org/t/psa-use-julia-0-7-if-you-are-upgrading/13321):
>
> A lot of people are posting issues where their old code doesn’t work anymore on 1.0 because some function has been renamed or removed. The 0.7 release exists exactly for this reason: your old code will work on 0.7 and give you a specific warning about how to fix your code. If you have any old code, you should use 0.7 to get these warnings before switching to 1.0; even if you just have work habits that may need changing, you should probably use 0.7 for a while. If someone posts an issue like thi…