I have been following the 2020 US election very closely, yes, it is still in the primary season, but I saw a Nolan Chart and thought that I had to create this in Tableau. So found this quite interesting, so hopefully, you will do as well.
Data
We will start by loading the following data into Tableau Desktop / Tableau Public.
| Politician | Social Issue Score | Economic Issue Score |
| Joe Biden | 80 | 15 |
| Mike Bloomberg | 80 | 30 |
| Pete Buttigieg | 73 | 30 |
| Tulsi Gabbard | 85 | 33 |
| Elizabeth Warren | 88 | 5 |
| Bernie Sanders | 98 | 3 |
| Amy Klobuchar | 70 | 10 |
| Donald Trump | 20 | 83 |
| Mike Pence | 10 | 95 |
| Andrew Yang | 83 | 20 |
| Marianne Williamson | 90 | 8 |
| Tom Steyer | 83 | 18 |
| Bill de Blasio | 85 | 13 |
| Julian Casto | 75 | 13 |
| Howard Schultz | 73 | 33 |
| Cory Booker | 80 | 18 |
This information has been collated from the On The Issues website, where they have tracked the positions of politicians and given it a score. You can read more about this here: https://www.ontheissues.org
Calculated Fields
With our data set loaded into Tableau, we are going to create the following Calculated Fields:
Hypotenuse
SQRT(SQUARE([Social Issues Score])+SQUARE([Economic Issues Score]))Yes, we get to use the Pythagorean theorem, I did not think I would ever have a need to use this.
Angle (Degrees)
DEGREES(ACOS(ZN([Economic Issues Score])/ZN([Hypotenuse])))Angle (Degree+45)
ZN([Angle (Degrees)]+45)Note: We are going to rotate the angle of the point by 45 degrees (we can make this dynamic, but for a Nolan Chart, 45 degrees is what we are looking for).
X
COS(RADIANS([Angle (Degree+45)]))*[Hypotenuse]Y
(SIN(RADIANS([Angle (Degree+45)]))*[Hypotenuse])-70.7Note: We subtract 70.7 to move the centre point to zero. For me, it just makes things a bit neater.
With this done, let us start creating our data visualisation.
Worksheet
We will now build our worksheet:
- Change the Mark Type to Circle
- Drag Politician to the Detail Mark
- Drag X onto the Column Shelf
- Drag Y onto the Rows Shelf
- Drag Social Issue Score onto the Color Mark
- Click on the Color Mark and select Edit Color
- Set Palette to Red-Blue Diverging
- Set Stepped Color to 2
- Click on Advanced and set Centre to 50
If all goes well, you should now see the following:
Now I want you to download the following background image:
This was created using a combination of Excel and GIMP, but we can use this forevermore. With the file downloaded, we will not apply this.
- In the menu go to Map, Background Images and then select your data source.
- Click on Add Image…
- In File or URL browse to the nolan-chart-background
- In X Field select X
- Make sure X is selected
- Set Left to -75
- Set Right to 75
- In Y Field select Y
- Make sure Y is selected
- Set Left to -75
- Set Right to 76
- Set the Washout to 50%
- Click Ok
You should now see the following:
With this, we now have our Data Visualisation functionally built. So now we will work on cosmetics:
- Fix the Y-Axis to be from -90 to 90
- Fix the X-Axis to be from -90 to 90
- Hide the X and Y-Axis Headers
- Remove all Grid Lines
- Remove all Zero Lines
- Edit the Tooltips
You should now want to end up with the following:
and boom, we are done! I hope you enjoyed creating this data visualization and learned some cool techniques as well. As always, you can find this data visualisation on Tableau Public at https://public.tableau.com/profile/toan.hoang#!/vizhome/NolanChart/NolanCharts
Summary
I hope you all enjoyed this article as much as I enjoyed writing it and as always do share the love. Do let me know if you experienced any issues recreating this Visualization, and as always, please leave a comment below or reach out to me on Twitter @Tableau_Magic. Do also remember to tag me in your work if you use this tutorial.
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- Patreon: https://www.patreon.com/tableaumagic
Also, do be sure to check out our various courses:
- Creating Bespoke Data Visualizations (Udemy)
- Introduction to Tableau (Online Instructor-Led)
- Advanced Calculations (Online Instructor-Led)
- Creating Bespoke Data Visualizations (Online Instructor-Led)
