Data visualisation is at the heart of everything we do here at Ansys, and we aren't alone! It resides at the heart of the purposes of many of our customers, competitors, and colleagues in this field. How you represent data visually is key to communicating and is actually a well-established field with a lot of literature compiled on the subject. There are plenty of annual conferences and papers published about it, so naturally we all listen to what they have to say at regular intervals to keep abreast of the best ways to communicate our complex numerical data?
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Ooh. Ah. Well. You see...
Part 1: What is Data Visualisation?
Data visualisation (or "DataViz" for short) is...
Visual communication of complex, often numerical, data through the use of lines, graphs, color and other diagrams.
But to break it down a little, that is what DataViz is, but why do we want to visualise our data? What do we get out of it?
Goal # 1 - Communicate accurately
The main reason is the most obvious. DataViz allows us to communicate complex data in a succinct, aesthetically pleasing form. For example, take the cosmic microwave background radiation (CMBR), which is a representation of the oldest light sources ever observed by man in our universe. Evidence of endlessly ricocheting electromagnetic radiation that's still around since the Big Bang. The plot below shows us very clearly what it looks like from Earth (taken from the ESA website "Planck and the cosmic microwave background").
It's incredible!
Secret Goal # 1 - Entertain/Engage the viewer
However, DataViz has a secret second goal, which is to entertain the viewer. Part of what captures the eye about the CMBR plot above is the color. The blues and the red showing the troughs and peaks of the radiation intensity. If we plot the same data in something less colorful, like a pure greyscale, a lot of the "life" goes out of it.
This goes double for commercial software. Your plots can be the most accurate in the world, but that won't matter one jot if no one will buy the software to begin with because the visualisations are too boring. People like color, and they'll apply it to everything they can.
Goal # 2 - Communicate succinctly
The secondary goal of DataViz in my opinion is communicate succinctly. The CMBR, for example, consists of tables and tables of data. To share the raw data would require pages and pages of numbers. Check it out on the NASA site, if you're interested. But the plot above condenses the key aspects of that info into a plot that's barely a couple of inches wide. It's quite incredible.
"a picture says a thousand words"
Well in DataViz
"A plot can say a thousand numbers, or more, sometimes a LOT more"
If it's good enough it may become so iconic that people start making plushies of it (see TheParticleZoo).
Secret Goal # 2 - Highlight/Draw attention to a specific aspect of the data
This brings us to the second secret goal that when presenting data to an audience the author's intent will affect the visualisation; sometimes consciously and sometimes subconsciously. The most neutral (in my opinion) presentation of data is in its raw form, as a table, but as discussed this is not particularly succinct or visually appealing. The message you wish to communicate with your data, as the author, will necessarily affect its presentation.
For example, let's consider a mechanical simulation of a car part. The software doing the simulation wants to communicate to the user if there are any failures and where those failures are. And it wants to communicate this at a glance. The viewer should be able to intuit "bad thing happened here" without needing to examine the scale. Which is a lot of words to say that the "bad" bits need to be bright, angry, even painful colors. Colors like bright red, or yellow. Red is shorthand in our society for "STOP", "ATTENTION", and similar attention-grabbing messages, so making the thing you want to highlight a bright red that contrasts sharply with the other colors is pretty common.
Sometimes there are the equivalent "good" areas that are fine, so you might be tempted to color them green or blue, which would give the viewer an unconscious sense of safety.
The Series
This is the first article in a series of four. Find links to the rest of the series here (as they are published):