# A question about sort

**URL:** <https://discourse.julialang.org/t/a-question-about-sort/42035>\
**Category:** Optimization (Mathematical)\
**Tags:** question\
**Created:** [June 25, 2020, 1:14pm UTC](https://discourse.julialang.org/t/a-question-about-sort/42035 "2020-06-25T13:14:04Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [June 25, 2020, 1:14pm UTC](https://discourse.julialang.org/t/a-question-about-sort/42035/1 "2020-06-25T13:14:04Z")

</div>

How do I sort by the imaginary part of a complex matrix?what function?  
thanks!

---

<div class="post-metadata">

**Author:** ![xiaodai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/xiaodai/32/15937_2.png) [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Post date:** [June 25, 2020, 1:19pm UTC](https://discourse.julialang.org/t/a-question-about-sort/42035/2 "2020-06-25T13:19:50Z")

</div>

`sort` has a `by` params so do this

`sort(x, by = imag)`

---

<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [June 25, 2020, 1:23pm UTC](https://discourse.julialang.org/t/a-question-about-sort/42035/3 "2020-06-25T13:23:10Z")

</div>

> [@xiaodai](#):
>
> sort(x, by = x-\>x[2])

nice!!!thank you !!!

---

<div class="post-metadata">

**Author:** ![xiaodai](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/xiaodai/32/15937_2.png) [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Post date:** [June 25, 2020, 1:23pm UTC](https://discourse.julialang.org/t/a-question-about-sort/42035/4 "2020-06-25T13:23:44Z")

</div>

> [@xiaodai](#):
>
> sort(x, by = x-\>x[2])

> [@xiaodai](#):
>
> sort(x, by = imag)

You clipped too early the 2nd one is correct

---

<div class="post-metadata">

**Author:** ![abcde](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abcde/32/16180_2.png) [@abcde](https://discourse.julialang.org/u/abcde)\
**Post date:** [June 25, 2020, 1:24pm UTC](https://discourse.julialang.org/t/a-question-about-sort/42035/5 "2020-06-25T13:24:20Z")

</div>

got it,thanks!!!