Tag: piechart

OriginLab’s Graph Gallery: A blast from the past

OriginLab’s Graph Gallery: A blast from the past

Continuing my recent line of posts on data visualization resources, I found another repository in my inbox: OriginLab’s GraphGallery!

If I’m being honest, I would personally advice you to look at the dataviz project instead, if you haven’t heard of that one yet.

However, OriginLab might win in terms of sentiment. It has this nostalgic look of the ’90s, and apparently people really used it during that time. Nevertheless, despite looking old, the repo seems to be quite extensive, with nearly 400 different types of data visualizations:

Quantity isn’t everything though, as some of the 400 entries are disgustingly horrible:

There’s so much wrong with this graph…

What I do like about this OriginLab repo is that it has an option to sort its contents using a random order. This really facilitates discovery of new pearls:

Thanks to Maarten Lambrechts for sharing this resource on twitter a while back!

Chatterplots

Chatterplots

I’ve mentioned before that I dislike wordclouds (for instance here, or here) and apparently others share that sentiment. In his recent Medium blog, Daniel McNichol goes as far as to refer to the wordcloud as the pie chart of text data! Among others, Daniel calls wordclouds disorienting, one-dimensional, arbitrary and opaque and he mentions their lack of order, information, and scale. 

Wordcloud of the negative characteristics of wordclouds, via Medium

Instead of using wordclouds, Daniel suggests we revert to alternative approaches. For instance, in their Tidy Text Mining with R book, Julia Silge and David Robinson suggest using bar charts or network graphs, providing the necessary R code. Another alternative is provided in Daniel’s blogthe chatterplot!

While Daniel didn’t invent this unorthodox wordcloud-like plot, he might have been the first to name it a chatterplot. Daniel’s chatterplot uses a full x/y cartesian plane, turning the usually only arbitrary though exploratory wordcloud into a more quantitatively sound, information-rich visualization.

R package ggplot’s geom_text() function — or alternatively ggrepel‘s geom_text_repel() for better legibility — is perfectly suited for making a chatterplot. And interesting features/variables for the axis — apart from the regular word frequencies — can be easily computed using the R tidytext package. 

Here’s an example generated by Daniel, plotting words simulatenously by their frequency of occurance in comments to Hacker News articles (y-axis) as well as by the respective popularity of the comments the word was used in (log of the ranking, on the x-axis).

[CHATTERPLOTs arelike a wordcloud, except there’s actual quantitative logic to the order, placement & aesthetic aspects of the elements, along with an explicit scale reference for each. This allows us to represent more, multidimensional information in the plot, & provides the viewer with a coherent visual logic& direction by which to explore the data.

Daniel McNichol via Medium

I highly recommend the use of these chatterplots over their less-informative wordcloud counterpart, and strongly suggest you read Daniel’s original blog, in which you can also find the R code for the above visualizations.

Xenographics: Unusual charts and maps

Xenographics: Unusual charts and maps

Xeno.graphics is the collection of unusual charts and maps Maarten Lambrechts maintains. It’s a repository of novel, innovative, and experimental visualizations to inspire you, to fight xenographphobia, and popularize new chart types.

For instance, have you ever before heard of a time curve? These are very useful to visualize the development of a relationship over time.

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Time curves are based on the metaphor of folding a timeline visualization into itself so as to bring similar time points close to each other. This metaphor can be applied to any dataset where a similarity metric between temporal snapshots can be defined, thus it is largely datatype-agnostic. [https://xeno.graphics/time-curve]
The upset plot is another example of an upcoming visualization. It can demonstrate the overlap or insection in a dataset. For instance, in the social network of #rstats twitter heroes, as the below example from the Xenographics website does.

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Understanding relationships between sets is an important analysis task. The major challenge in this context is the combinatorial explosion of the number of set intersections if the number of sets exceeds a trivial threshold. To address this, we introduce UpSet, a novel visualization technique for the quantitative analysis of sets, their intersections, and aggregates of intersections. [https://xeno.graphics/upset-plot/]
The below necklace map is new to me too. What it does precisely is unclear to me as well.

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In a necklace map, the regions of the underlying two-dimensional map are projected onto intervals on a one-dimensional curve (the necklace) that surrounds the map regions. Symbols are scaled such that their area corresponds to the data of their region and placed without overlap inside the corresponding interval on the necklace. [https://xeno.graphics/necklace-map/]
There are hundreds of other interestingcharts, maps, figures, and plots, so do have a look yourself. Moreover, the xenographics collection is still growing. If you know of one that isn’t here already, please submit it. You can also expect some posts about  certain topics around xenographics.

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A note on Pie Charts

A note on Pie Charts

A table is nearly always better than a dumb pie chart; the only worse design than a pie chart is several of them […] pie charts should never be used.

Edward Tufte in the Visual Display of Quantitative Information

Stop using pie charts, they are evil!

title of Bernard Marr’s LinkedIn post

I hate pie charts. I mean, really hate them.

Cole Nussbaumer in death to pie charts

Many people have criticized the pie chart. The most important critique is that we, humans, are good in comparing lengths and heights, but angles and areas not so much. The following three charts by Kristin Henry demonstrate the phenomenon. Can you spot how the two pie charts below are different? 

And how about now?

OK, I admit that the order of the categories matters quite a lot in the chart above. But alternatively, you can transform the pie charts into grouped bar charts, that will immediately show the difference: 

In general, pie charts should be avoided when a large number of items is considered. Simple pie charts displaying 2-3 categories or one category as opposed to the others may work just fine, but when displaying more data, it is better to choose a different chart type. Oracle hosted a different example some years back:

Data Visualization - Pie Chart Angles

Fortunately, there is some constructive criticism as well. Cole Nussbaumer of storytellingwithdata.com provides some good alternatives to pie charts and David Robinson of VarianceExplained.org does provides alternative charts specifically in R. Datawrapper.de discusses when pie charts may come in handy and when they should definately not be used. Finally, the below GIF funnily shows the steps in which pie charts can be improved:

Pie charts have been used for jokes before, arguably their only good purpose:

Image result for the only good use of a pie chart
(image from Denovo Group)

On a final note, there do seem to be even worse visualizations of data than pie charts:

Data Visualization - Stacked Donut Chart
This monstrosity is apparently called a stacked donut chart (OpenDataScience.com)