# Quick way to create a vector of only rationals wthin a range?

**URL:** <https://discourse.julialang.org/t/quick-way-to-create-a-vector-of-only-rationals-wthin-a-range/107189>\
**Category:** General Usage\
**Tags:** rationals, vector\
**Created:** [December 6, 2023, 12:46am UTC](https://discourse.julialang.org/t/quick-way-to-create-a-vector-of-only-rationals-wthin-a-range/107189 "2023-12-06T00:46:57Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![PeX](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pex/32/49986_2.png) [@PeX](https://discourse.julialang.org/u/PeX)\
**Post date:** [December 6, 2023, 12:46am UTC](https://discourse.julialang.org/t/quick-way-to-create-a-vector-of-only-rationals-wthin-a-range/107189/1 "2023-12-06T00:46:57Z")

</div>

Hi all,  
I want to create a vector of 30 rational numbers between 10^(-5) to 10^(-1). Preferably evenly spaced.  
Is there a quick and efficient way to do it in Julia?

Thank you!

---

<div class="post-metadata">

**Author:** ![contradict](https://avatars.discourse-cdn.com/v4/letter/c/ac91a4/32.png) [@contradict](https://discourse.julialang.org/u/contradict)\
**Post date:** [December 6, 2023, 1:10am UTC](https://discourse.julialang.org/t/quick-way-to-create-a-vector-of-only-rationals-wthin-a-range/107189/2 "2023-12-06T01:10:48Z")

</div>

Depends on what you mean by ‘evenly spaced’

For linear spacing:

```julia
range(start=1//100000, length=30, stop=1//10)

```

For log spacing, maybe

```julia
rationalize.(10 .^ range(start=-5, length=30, stop=-1))

```

---

<div class="post-metadata">

**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [December 6, 2023, 2:18am UTC](https://discourse.julialang.org/t/quick-way-to-create-a-vector-of-only-rationals-wthin-a-range/107189/3 "2023-12-06T02:18:17Z")

</div>

Technically, all finite floating-point values are rational, so no need to use `Rational` here.