# What is defination of dims

**URL:** <https://discourse.julialang.org/t/what-is-defination-of-dims/47878>\
**Category:** Optimization (Mathematical)\
**Created:** [October 6, 2020, 6:25pm UTC](https://discourse.julialang.org/t/what-is-defination-of-dims/47878 "2020-10-06T18:25:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Batuhan\_Guvenc](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/batuhan_guvenc/32/15422_2.png) [@Batuhan\_Guvenc](https://discourse.julialang.org/u/Batuhan_Guvenc)\
**Post date:** [October 6, 2020, 6:25pm UTC](https://discourse.julialang.org/t/what-is-defination-of-dims/47878/1 "2020-10-06T18:25:12Z")

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search func which gives sum of every matris rows in a list  
for matris like this  
1 0 1  
0 1 0  
output [2,1]  
i fins sum(list,dims=2) func but i dont want use this for examle i use " +(list…) "instead of "sum(list) "i find it in definition but i cant find dims defination there are defination for dims ? maybe there can be “.” or func . how dims can select each rows and makes it very fast

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**Author:** ![tbeason](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tbeason/32/15898_2.png) [@tbeason](https://discourse.julialang.org/u/tbeason)\
**Post date:** [October 6, 2020, 6:39pm UTC](https://discourse.julialang.org/t/what-is-defination-of-dims/47878/2 "2020-10-06T18:39:14Z")

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Completely unclear what you want to do. I’ll try to help anyway. Next time please quote your code with backticks.

```julia
a = [1 0 1; 0 1 0]
X = (a,a)
sum.(X,dims=2)

```

Does that help?