Data Viz Done Right

February 23, 2021

Four Methods for Creating a Seismogram

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A Seismogram is an alternative to a circle timeline. They are a great way of showing change over time, and are particularly effective when there are big variations in the dataset.

In this video, I show you how to build several version of a Seismogram:

1. Discrete Dates with horizontal lines
2. Continuous Dates with horizontal lines
3. Continuous Dates with vertical lines
4. Gantt chart Seismogram

February 22, 2021

#MakeoverMonday Week 8 - Protests Against Limiting Abortion Rights in Poland

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On 22nd of October 2020, in the middle of a pandemic, the Constitutional Tribunal of Poland ruled abortion in case of fetal malformations unconstitutional. In this week's Makeover Monday, I ask where and when were the protests that followed?

Watch Me Viz

February 16, 2021

Understanding Table Calcs vs LODs: Explained with a Slope Graph

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Table calculations and LODs, especially understanding the difference between when to use each, is one of the most difficult concepts to learn in Tableau. Through my time teaching, one of the most effective means for explaining the differences between them is with a simple slope graph.

The idea is to color each line of the slope graph by whether it represents an increase or a decrease. You'd think this would be super simple, but it's not. In this video, I show you:

1. How to write the required calculations
2. The benefits of table calcs vs. LODs
3. Why table calcs are often more flexible

My general rule of thumb: If all of the dimensions I need for the calculation I want to write are already in the view, start with a table calculation. If all of the dimensions I need are NOT in the view, then you must use a level of detail expression.

Download the sample data set here -

February 15, 2021

#MakeoverMonday Week 7 - What is most important on Valentine's Day?

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It's Valentine's Day and what's the point? In this #WatchMeViz session, I explored lots of visualization before settling on a viz that was basically the same as the original with the exception of the colors, title and interactivity. Enjoy!

February 9, 2021

How to Assign Highlight Colors to Palette

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You can use a parameter to highlight a particular dimension in a chart. But there's a much easier and quicker method. The option is on the color legend. 

It's simple:

1. Click on a color to highlight it.
2. From the color legend drop down, choose Assign Highlight Colors to Palette.

February 8, 2021

#MakeoverMonday Week 6: Why Are Women Perceived to Be Unequal to Men?

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Wow! What a fun #WatchMeViz that was! I iterated through 16 charts and then when the idea solidified, there was some great conversation and feedback on the chat to help me get to the end. I find survey responses quite difficult to visualize, so instead of getting frustrated, I thought about all of the ways I can compare data to see if anything would work.

Most importantly, thank you to all of your on the live chat. It makes a huge difference to me and I love getting your feedback and questions along the way. You make me better. You can find the final visualization below the video.

February 4, 2021

How to Add Zeros for Missing Time Series Data

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When working with time series data, Tableau understands how to populate dates that don't exist. For example, if you have sales for Jan 3 and Jan 5, Tableau can "add" data for Jan 4.

Great! But then you want to show zero in that cell. This tip shows you how to do just that.

February 2, 2021

How to Create a Trellis Chart in Seven Steps

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Trellis charts are a version of a small multiples chart that organizes the dimensions in the view across a grid. In this tip, I show you how to create a trellis chart that will work even when you are missing data.

Trellis / Panel Chart Calculations


int( (index()-1)/(round(sqrt(size()))))


  1. Create the column and row calcs
  2. Create a custom date
  3. Place custom date on columns, measure on rows and dimension on detail
  4. Place column on columns, row on rows, and custom date on detail
  5. Ensure dimension is above date on detail shelf
  6. Change custom date on columns to ATTR
  7. Configure table calcs
    1. Check both the Dimension and the date field date in order
    2. Ensure the dimension is above the date field in the Specific Dimensions section
    3. Set "At the level" to the dimension

Follow along in this video. Enjoy!

February 1, 2021

#MakeoverMonday Week 5 - Renewables vs Fossil Fuels in Europe

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I found this week's data set super interesting. There was so much to explore. I could probably have gone for hours trying different charts and making lots of comparisons. Here's the video from the Watch Me Viz session.



Overall, I think this is a very good chart. 

  • The colors are perfect for the topic.
  • I like the labels on the ends of the lines.
  • The tooltips are very responsive and color-coded to match the line.
  • The title and subtitle are informative and give good context.
  • The slightly lighter shading of the axes labels make the chart stand out more.


  • Make the dashed lines solid.
  • Format the percentages in the tooltip to one decimal place.


Click on the image or here for the interactive version.

January 26, 2021

Three Methods for Creating Bar Charts that Fill to 100%

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Bar charts that show % of total or percentages below 100% can be made to look a bit nicer by including a color that shows the remainder of the bar chart going up to 100%. 

In this video, I show you three methods for creating bar charts that go up to 100% by including another field in the view.

Download the data I used here to follow along.

January 25, 2021

#MakeoverMonday Week 4 - Coal Production in India

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  1. Watch Me Viz - (also below)
  2. Tableau Workbook -

I'd been looking for a data set about India for quite a while now in an effort to keep the Makeover Monday Community in India engaged. This week, I found one about coal production at various mines across the country. It was an interesting topic to learn about, including why the research was done and the purpose. Read the manuscript for background info here.

The original visualization was a simple bar chart of coal production by District.

What could be improved?

  • There's no title.
  • The District names are way too small. My old eyes can't read it.
  • I don't understand the sorting. I would pick one of the metrics to sort by.
  • The comparisons need to be more clear, if that is the intent.

Watch Me Viz

To see what I built, check out the video below. I iterated through all of the dimensions with a series of bar charts to understand the data. Thank you very much to those that watched to help me understand what some of the values meant!! I ended up with a simple dashboard that allows you to explore the data by producer and mine within each State. See the viz below the video or here.

Final Dashboard (click to interact)

January 19, 2021

How to Apply Formatting Across Worksheets

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Formatting can be an arduous task, sometimes taking more time than creating the visualization. In this tip, I show you how to apply the formatting you have so carefully created in one worksheet to another worksheet with only a couple of clicks.

January 18, 2021

#MakeoverMonday Week 3 - The World is Getting Warmer

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This week's viz to makeover reminded me of a very similar (almost exactly the same) data set that we used for Makeover Monday in 2016. Here's the original viz:

Honestly, it's absolutely fantastic. It's one of the best examples of scrollytelling I've every seen. Check out the original here

Since I had explored this data set before, I know pretty quickly what I wanted to do. During Watch Me Viz, I went ahead through many iterations of working with time series data; they're all available in the workbook. Watch the video here (or below).

Here's my final viz. Each dot represents a month and the line represents at 10-year moving average. Each mark is compared to the 1951-1980 median. Click on the image to view the viz on Tableau Public.

January 13, 2021

How to Create a Candlestick Chart

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 What is a Candlestick Chart?

A candlestick chart is a style of financial chart used to describe price movements of a security, derivative, or currency. Each "candlestick" typically shows one day, thus a one-month chart may show the 20 trading days as 20 candlesticks. Candlestick charts can also be built using intervals shorter or longer than one day.

It is similar to a bar chart in that each candlestick represents all four important pieces of information for that day: open and close in the thick body; high and low in the “candle wick”. Being densely packed with information, it tends to represent trading patterns over short periods of time, often a few days or a few trading sessions.  

~ Source: Wikipedia

In this tutorial, I show you how to build a candlestick chart in Tableau. They are built as Gantt charts with a couple of simple calculations. Follow along by downloading the data set here

January 11, 2021

#MakeoverMonday 2021 Week 2 - Women Die More Quickly Than Men From HIV Infection

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I must admit that I REALLY struggled with this data set. I could have easily just compared males vs. females by country and year, but it seems we've been doing that over and over again. I looked to explore the data and thought a connected scatterplot would look nice, but it didn't.

Fortunately Michel Mahon proposed looking at the lag between the year of HIV infection rate and death. Morbid yet interesting analysis. It took me a while to get the calcs working; I'd recommend you build your view as a table to verify the calcs when you're not sure if they're correct. In the end, thanks to Michel's suggestion, I created a slope graph that compares the lag in years for both men and women.

As the documentation suggested, women die more quickly than men.

Below are both my visualization and the Watch Me Viz session on YouTube. Thanks for tuning in!

January 3, 2021

#MakeoverMonday 2021 Week 1: Quiet Streets & Clean Air - Americans Are Getting Outdoors

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Back in March 2020 when COVID lockdown started in the UK, the streets were amazingly empty, the air got fresher and I saw more and more people outside. You could hear birds chirping on streets you never would have before. And we could ride our bikes right down the middle of the road since there were no cars. The lack of cars was glorious! (COVID isn't of course).

For 2021, #MakeoverMonday gets started with a simple graphic that compares pedestrian and bicycle counter stats for 2019 and 2020 at 31 counters across America. The data is collected by the Rails to Trails Conservancy, and you can learn more about the data here



  • A line chart is a good choice for time series data.
  • The colors are easy to distinguish.
  • The grid lines help guide the eye across the view.


  • Include a more impactful or descriptive title. What is it about?
  • Why are thee weeks missing on the x-axis yet the lines go the full year (or appear to)?
  • The lines could be labeled directly so that you don't have to refer to the color legend to know which lines represents which year.


December 17, 2020

How to Create a Dot Matrix Plot

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Dot matrix charts are useful for visualizing the distribution and frequency of discrete data. They help you understand the scale and proportion. The purchase is to understand how many, not how much. 

In this example, I'm using two colors to distinguish new vs. used cars. However, if you have only one variable or category, then stick to one color.


  1. Workbook -
  2. Data set -

December 8, 2020

#TableauTipTuesday: How to Sort a Chart with a Parameter Action

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In this tip, I show you how to use a parameter action to sort a stacked bar chart. This technique can also be applied to other chart types.

There are seven steps:

  1. Build the chart
  2. Create a parameter
  3. Create a calculated field to sort the bars, then sort the Region field.
  4. Create de-highlight calculated field and place it on the Detail shelf
  5. Create a Parameter Action
  6. Create a Highlight Action
  7. Turn on Animations


December 1, 2020

How to Create an Evenly Distributed Butterfly Chart

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A Butterfly Chart is (typically) a bar chart where two sets of data series are displayed side by side. The purpose is to allow you to compare the two data series across a dimension. 

Here is an example of a butterfly chart I created for Makeover Monday.

Notice how I have zero at the center and the scales are the same on either side of zero. This helps show how the chart "leans" to one side or the other.

The comparisons would be more difficult to see if the left and right hand sides of the butterfly did not have the same axis scale. In this video, I show you how two examples for creating a butterfly chart.

November 26, 2020

How to Create U.S. Electoral Cartograms

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I don't remember how I came across the set of cartograms I'm going to show you how to create. Alas, I wanted to recreate this mesmerising set of cartograms that Noah Veltman created based on election maps from various media outlets.

Noah's page contains the vector files for each map. I saved them individually and prepped the data in Alteryx so that I could build the polygons in Tableau. Download the workflow here.

I needed to create two branches because some of the States are divided up into parts. For example, Maine in the NPR map has four blocks since Maine allocates each of its four electoral college votes separately. This required the same steps to be reproduced twice. For those States with multiple blocks, I had to split out each block, pivot them, then split those results, and pivot one more time.

Once I had the CSV, it was pretty easy to build in Tableau.

  1. X on the Columns
  2. Y on the Rows (and reverse the axis)
  3. Set both X and Y to AVG
  4. Change the mark type to Polygon
  5. Add the Path field to the Path shelf (this tells table how to connect the edges of the polygon)
  6. Add the State field to the Detail shelf

From there, it was some formatting for the colors, etc. This process, I would think, would work for any SVG (vector) file. This was a fun little project. I learned a lot!