# TL;DR tips for Julia users coming from Matlab
**URL:** https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093
**Category:** General Usage
**Created:** [June 9, 2020, 8:28pm UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093 "2020-06-09T20:28:08Z")
**Posts on this page:** 9
**Page:** 2
### Author:  [@Zach\_Christensen](https://discourse.julialang.org/u/Zach_Christensen)
#### Post date: [June 10, 2020, 10:40am UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/22 "2020-06-10T10:40:38Z")
This is amazing! I’m going to present to my lab in a couple weeks and this will be a great resource for everyone else.
---
### Author:  [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)
#### Post date: [June 10, 2020, 11:36am UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/23 "2020-06-10T11:36:32Z")
> [@jlchan](#):
>
> The example `x = f(x)` by itself might be oversimplified. I see type instability when redefining variable names using anonymous functions
Interesting, the reason for this is [performance of captured variables in closures · Issue #15276 · JuliaLang/julia · GitHub](https://github.com/JuliaLang/julia/issues/15276) and you can show it more succinctly with:
```julia
function not_type_stable(a)
a = a # toggle comment on this line
return (x->x+a)(1)
end
```
So while I guess it is true that in some cases, assignments to a variable can cause performance problems, the reason isn’t really that `a` has one type and then you assign it to another type.
---
### Author:  [@DNF](https://discourse.julialang.org/u/DNF)
#### Post date: [June 10, 2020, 12:19pm UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/24 "2020-06-10T12:19:16Z")
> [@roble](#):
>
> Another difference is, that any Matlab vector is just a row or column matrix.
This is one of those habits that many appear to be blind towards. New users are so often initializing arrays as
```julia
zeros(n, 1)
rand(n, 1)
# etc.
```
when they almost always should use
```julia
zeros(n)
rand(n)
# etc.
```
They’re not even going to think about it unless it’s pointed out directly. It’s a semi-subconscious assumption about how vectors work.
Similarly, use `rand()` instead of `rand(1)` or `rand(1)[1]`.
---
### Author:  [@kevbonham](https://discourse.julialang.org/u/kevbonham)
#### Post date: [June 10, 2020, 12:34pm UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/25 "2020-06-10T12:34:16Z")
> [@ettersi](#):
>
> You cannot have an immutable container with changing lengths,
I hate to be pedantic\*, but
```julia
julia> struct Foo
x::Vector
end
julia> Base.length(f::Foo) = length(f.x)
julia> Base.push!(f::Foo, a) = push!(f.x, a)
julia> foo=Foo([])
Foo(Any[])
julia> length(foo)
0
julia> push!(foo,1)
1-element Array{Any,1}:
1
julia> length(foo)
1
```
\*That’s not true. I really enjoy bring pedantic 🤪. You’re off course correct.
---
### Author:  [@DNF](https://discourse.julialang.org/u/DNF)
#### Post date: [June 10, 2020, 12:54pm UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/26 "2020-06-10T12:54:16Z")
Totally correct! Here’s another example of the same:
```julia
julia> struct Bar end
julia> Base.length(::Bar) = rand(0:1000)
julia> b = Bar()
Bar()
julia> length(b)
338
julia> length(b)
129
```
😉
---
### Author:  [@jonathanBieler](https://discourse.julialang.org/u/jonathanBieler)
#### Post date: [June 10, 2020, 1:34pm UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/27 "2020-06-10T13:34:13Z")
```julia
linspace(a,b,n) = range(a; stop=b, length=n)
logspace(a,b,n) = 10 .^ range(a; stop=b, length=n)
```
---
### Author:  [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)
#### Post date: [June 10, 2020, 7:53pm UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/28 "2020-06-10T19:53:27Z")
When I first transitioned from matlab to Julia, I set up atom snippets for some common functionality like this.
That way I could type the old matlab stuff but get the new Julia stuff without any additional function definitions. Here are some
>
---
### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [June 11, 2020, 6:34am UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/29 "2020-06-11T06:34:34Z")
> [@kevbonham](#):
>
> I hate to be pedantic
I love to be pedantic 😉 I am wondering if we should keep using the term “immutable” for these kinds of constructs in discussions. An “(immutable) `struct`” is a clearly defined concept in Julia, but `Foo` above may not mesh well with what various people understand as “immutable”.
Mutability (or lack thereof) in Julia is a very narrowly defined technical term that is meaningful mostly for composite types.
---
### Author:  [@Bardo](https://discourse.julialang.org/u/Bardo)
#### Post date: [October 11, 2021, 4:44pm UTC](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093/30 "2021-10-11T16:44:40Z")
> [@jlchan](#):
>
> The manual is great, but I’ve found myself reading over parts without realizing that they applied to my current situations. I’ve found TL;DR explanations to be helpful in knowing where to look for information, not to replace more precise technical explanations.
Same here. An otherwise pleasant Julia experience can be brought to a longer halt if help is not accessible.
Also had this [tldr-pages](https://github.com/tldr-pages/tldr) or this [navi](https://www.reddit.com/r/bash/comments/q5wjj6/a_tool_that_autocompletes_your_bash_commands/) idea (in previous posts I called for one-liners or snippets).
We often ask posters to provide a minimum working example.
I wondered if we could expect the same from someone answering a question, or contributes to Julia?
Sounds ungrateful? Since it’s all free and based on voluntary work.
You are all doing a great job - thanks!
My only argument is that a help that is not understood is a lost effort.
Maybe you developers and helpers can go a bit further, think of the not-so-progressed, and add some TL;DR examples.
[Previous page](https://discourse.julialang.org/t/tl-dr-tips-for-julia-users-coming-from-matlab/41093.md?page=1)