# Plotting Quantities with Astropy

**URL:** <https://community.openastronomy.org/t/plotting-quantities-with-astropy/939>\
**Category:** Astropy\
**Created:** [March 12, 2024, 4:17pm UTC](https://community.openastronomy.org/t/plotting-quantities-with-astropy/939 "2024-03-12T16:17:55Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![garywil](https://avatars.discourse-cdn.com/v4/letter/g/a4c791/32.png) [@garywil](https://community.openastronomy.org/u/garywil)\
**Post date:** [March 12, 2024, 4:17pm UTC](https://community.openastronomy.org/t/plotting-quantities-with-astropy/939/1 "2024-03-12T16:17:55Z")

</div>

Using this example from the Astropy documentation:  
[https://docs.astropy.org/en/stable/visualization/matplotlib\_integration.html#plotting-quantities](https://docs.astropy.org/en/stable/visualization/matplotlib_integration.html#plotting-quantities)  
if I modify the quantity specification so that it is specified like this:  
plt.plot([1\* u.m, 2\* u.m, 3\* u.m] )  
rather than this:  
plt.plot([1, 2, 3] \* u.m)  
I get a unit conversion error. Any idea how I can get this to work? (My real data is like the former rather than the latter.)

---

<div class="post-metadata">

**Author:** ![ayshih](https://dub1.discourse-cdn.com/flex005/user_avatar/community.openastronomy.org/ayshih/32/84_2.png) [@ayshih](https://community.openastronomy.org/u/ayshih)\
**Post date:** [March 12, 2024, 6:37pm UTC](https://community.openastronomy.org/t/plotting-quantities-with-astropy/939/2 "2024-03-12T18:37:17Z")

</div>

Assuming that your quantities are all the same type of unit (e.g., length), you can instantiate a single `Quantity` object with your array, e.g.,:

```auto
plt.plot(u.Quantity([1* u.m, 2* u.m, 3* u.m]))

```

Hope that helps!

---

<div class="post-metadata">

**Author:** ![garywil](https://avatars.discourse-cdn.com/v4/letter/g/a4c791/32.png) [@garywil](https://community.openastronomy.org/u/garywil)\
**Post date:** [March 12, 2024, 6:57pm UTC](https://community.openastronomy.org/t/plotting-quantities-with-astropy/939/3 "2024-03-12T18:57:10Z")

</div>

Thanks, that worked!