#TweakThursday 19: ASCII as Data Marks

ASCII (and Unicode) characters can offer a variety of lightweight data marks. Judicious choices of context-sensitive data marks can create more interest in the eyes of the viewer and lead to better visualizations.

Especially in tooltips, we are limited to using ASCII/Unicode characters. Some of them can be used as data marks to provide data visualizations. ASCII art have been around for a long while. With ASCII, we can create very expressive art form if we dare to be creative.

For example, in restaurant ratings, we have seen expressions like

Expensive: $$$
Moderate: $$
Cheap: $

Depending on countries and being consistent with context, we can replace the above $ by € or ‎¥.

In various ratings such as movies or product reviews, we have seen stars being widely used.

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So this is not something new. What is new is we can use them in Tableau's tooltips to create lightweight data visualization that complements and enhance the primary charts. This has been advocated by Andy Cotgreave. Recently new Zen Master Rody Zakovich showed some more tricks. Especially the formula Replace(Space(),' ','█') is very convenient for creating a long string of any character.

In a recent viz of the day on 10/18/2016, I found that the vertical bars are hard to compare in height between Clinton and Trump numbers. This can be remedied by adding a little ASCII chart in tooltips.

Note that we used ▲ and ▼ as data marks to represent upward/downward trends. Also we added green color for up and red color for down. This seems more context sensitive than the bar chart based on '█'.

That concludes the tweak today. Click the images for interactive versions.

(Refresh the page if you want to view the gif image multiple times. Or go to Tableau Public and click the button at the top-right corner.)

Jake and I collaborated on a dashboard. He told me that he learnt a way to create an in-place help page in Tableau. He first saw it at a conference somewhere and couldn't recall who the speaker was. So I am blogging here about it but the credit goes to somebody else. If anyone knows who the original creator is, leave a comment below.

The key idea is to float a semi transparent worksheet on top of the dashboard, where a help text box is strategically placed on top of each chart. This way, we can explain how to view each chart and what data points are important, etc. This worksheet is collapsible by a show/hide button.

Below I would like to show how this worksheet can be constructed.

1. Sheet with a single data mark.

Double click the empty space in Marks panel and add two single quotes. Make the null pill a text label. This creates a single null mark.
Set the view as "Entire View"

2. Create an show/hide button

Go to the target dashboard
Drag a floating vertical container to the dashboard, making it cover all the area of interest.
Drag the Single Null Mark sheet and drop it into the above container. Hide the sheet title.
Create an open/close button for the container and place the button at the top-right corner.

3. Add annotations

Format the sheet background opacity as 70% in the layout manager
Select area annotations and place them anywhere of interest.
Write help text and format it to highlight important messages.
The text can serve as functional guide and/or insight guide.

Here is an example. Feel free to download the workbook and explore. Click the "i" button at the top-right corner to view the in-place help.

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Vizible Difference

In search of data visualization excellence

1. Sheet with a single data mark.

2. Create an show/hide button

3. Add annotations

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