31:T1aa9,# Plot in Action **[Irene de La Torre](https://observablehq.com/@irenedelatorre)** created the notebook **“[Comparing Placebo vs. Active treatments](https://observablehq.com/@irenedelatorre/comparing-placebo-vs-active-treatments?utm_campaign=plotpromo&utm_source=mail)”** to show the DLQI (Dermatology Life Quality Index), a measure of the quality of life for patients with different skin conditions such as psoriasis. [

](https://observablehq.com/@irenedelatorre/comparing-placebo-vs-active-treatments?utm_campaign=plotpromo&utm_source=mail) In the notebook, Irene describes some of the visualization techniques she used: _“I tried to strengthen the comparison between both treatments: instead of using opacity for describing the flow of patients, I used the stroke width of the lines. I also tried to be more descriptive around the items of DLQI.”_ See Irene’s example # #30DayChartChallenge The data visualization community is engaged in a [30 day chart challenge](https://observablehq.com/search?query=30daychartchallenge&utm_campaign=plotpromo&utm_source=newsletter), and several Observable users have created some great examples. Violeta Roizman is using Observable Plot to create a map of [all the trees in her hometown Buenos Aires](https://observablehq.com/@violetr/30daychartchallenge-day-4-flora); Shruti Mukhtyar is [faceting energy data](https://observablehq.com/@mukhtyar/day-3-historical); Advaith Venkatakrishnan is making [balls with basketball data](https://observablehq.com/@adv1996/april-2022-day-3-30daychartchallenge-historical); Tereza Iofciu is analyzing [gender diversity in the German Bundestag](https://observablehq.com/@terezaif/diversity-in-the-german-bundestag-2022), Adolfo Guimaraes is showing [who has internet access in Brazil](https://observablehq.com/@adolfoguimaraes/30daychartchallenge-day1), and more are coming every day. [

](https://observablehq.com/@violetr/30daychartchallenge-day-4-flora?utm_medium=newsletter&utm_campaign=plotpromo&utm_source=mail) _Violeta's map_ It’s not too late to join the challenge, which is open to everyone. Have fun trying out new techniques, and learn a few tricks along the way. The community is [here to help](https://talk.observablehq.com/) if you have questions or want to find a partner and collaborate on a chart. Check out the submissions! --- # Questions from the Community: Diverging bar chart and Likert scales In the Observable Forum, Eitan Lees [asked](https://talk.observablehq.com/t/diverging-stacked-bar-chart-in-plot/6028): *“I am interested in creating a diverging stacked bar chart to visualize some survey data. I have attached a sample notebook. What I would like to do is transform each bar to be aligned such that the “Neutral” category is centered on the x-axis about zero. I am using the [Robbins & Heiberger](http://www.asasrms.org/Proceedings/y2011/Files/300784_64164.pdf) paper as a reference.”* That is a _great_ way of asking a question, with a notebook, a dataset, and a scientific reference! When analyzing the answers to a survey, it is quite common to use a semantic differential (or Likert) scale, with answers being categorized as negative, others positive, and possibly a neutral option in the middle. In our answer, we focused on how to create a custom transform to implement this type of chart. This gave us an idea for [a new feature](https://github.com/observablehq/plot/pull/814) that is now available in the new version of Plot. Thank you, Eitan! If you have a question, please [visit the Forum](https://talk.observablehq.com/). [

](https://observablehq.com/@observablehq/plot-diverging-stacked-bar) See this example --- # A collection of 50+ Plot examples **[Plot Examples](https://observablehq.com/collection/@observablehq/plot-examples?utm_medium=newsletter&utm_campaign=plotpromo&utm_source=mail)** is a collection of 50+ real-world examples using Observable Plot. Curated from our team’s or many other Observable users’ notebooks, you will find grid choropleths, bump charts, plots of plots, COVID-19 timelines, rain clouds and UpSet charts, spine charts, ISOTYPE dot plots, and many more. And this is just the beginning! [

](https://observablehq.com/collection/@observablehq/plot-examples?utm_medium=newsletter&utm_campaign=plotpromo&utm_source=mail) Visit the Plot Examples collection --- # 30 Second Plot Video [

](https://youtu.be/t4grbTQJg30?utm_medium=newsletter&utm_campaign=plotpromo&utm_source=mail) Watch as we use Observable Plot to create a bar chart and add a filter using the "Select" Input, all in just 30 seconds! We've published [the notebook](https://observablehq.com/@observablehq/what-do-people-buy-on-bandcamp?utm_medium=newsletter&utm_campaign=plotpromo&utm_source=mail) featured in the video if you are interested. --- # Upcoming Events & Learning opportunities 📅 Join us on **April 26, 2pm PDT,** for the _Plot Happy Hour_! We'll have some examples prepared for you and will be answering your questions. [Sign up here!](https://www.meetup.com/observablehq/events/285156183/) *If you would like to host a future Observable Plot Meetup, please contact us at plot@observablehq.com* --- *This issue was edited by [Fil](https://observablehq.com/@fil), [Lauren](https://observablehq.com/@buchman), [Toph](https://observablehq.com/@tophtucker), [Dunstan](https://observablehq.com/@dunstan), and [Ian](https://observablehq.com/@enjalot). Please reach out to us by emailing plot@observablehq.com with your suggestions for the next issue.*
32:[] 2f:{"title":"Plot Twist, April 2022","cells":[{"id":10,"value":"# Plot Twist, April 2022\n\n*Plot Twist* is the newsletter about [Observable Plot](https://observablehq.com/plot?utm_campaign=plotpromo&utm_source=mail). Every month or so, we highlight the inspiring work being done in Observable Plot by creators from our growing user community. We also provide development updates, showcase new features, share examples and best practices.\n","pinned":false,"hidden":false,"mode":"md"},{"id":447,"value":"placeholder: Subscribe to the Plot Twist Newsletter.","pinned":false,"hidden":false,"mode":"md"},{"id":442,"value":"$31","pinned":false,"hidden":false,"mode":"md"},{"id":318,"value":"type = \"plot\"","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W32","stdlib":"1","titling":"auto"}