# Weird notation

**URL:** <https://discourse.julialang.org/t/weird-notation/1962>\
**Category:** General Usage\
**Created:** [February 7, 2017, 7:01pm UTC](https://discourse.julialang.org/t/weird-notation/1962 "2017-02-07T19:01:24Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Emerson\_Vitor\_Castel](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/emerson_vitor_castel/32/2933_2.png) [@Emerson\_Vitor\_Castel](https://discourse.julialang.org/u/Emerson_Vitor_Castel)\
**Post date:** [February 7, 2017, 7:01pm UTC](https://discourse.julialang.org/t/weird-notation/1962/1 "2017-02-07T19:01:24Z")

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Traditionally, | v |=max(|v\_i|). But in Julia we have:

julia\> v=[1.0 2.0 -5.0]  
1×3 Array{Float64,2}:  
1.0 2.0 -5.0

julia\> norm(v)  
5.477225575051661

julia\> norm(v,2)  
5.477225575051661

julia\> norm(v,Inf)  
8.0

julia\> norm(v,1)  
5.0

In my opinion it is changed, that is, I guess that the correct way is norm(v,Inf)=5 and norm(v,1)=8. Am I wrong?

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<div class="post-metadata">

**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [February 7, 2017, 7:22pm UTC](https://discourse.julialang.org/t/weird-notation/1962/2 "2017-02-07T19:22:17Z")

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Right now you are computing the matrix norm since `v` is a matrix. Either use `vecnorm` or actually make `v` a vector.

```julia
julia> v = [1, 2, -5]
n3-element Array{Int64,1}:
  1
  2
 -5

julia> norm(v, 1)
8.0

julia> norm(v, Inf)
5.0

```

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<div class="post-metadata">

**Author:** ![Emerson\_Vitor\_Castel](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/emerson_vitor_castel/32/2933_2.png) [@Emerson\_Vitor\_Castel](https://discourse.julialang.org/u/Emerson_Vitor_Castel)\
**Post date:** [February 7, 2017, 7:40pm UTC](https://discourse.julialang.org/t/weird-notation/1962/3 "2017-02-07T19:40:26Z")

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Ok, I get it! My mistake! Thank you!