I’m a little late on this, so I hope it’s old news to most readers that Universal Mind, where I’ve worked for the past 2 months, just launched a technology preview of the SpatialKey visualization system. This is a big deal.
Andrew Powell, Doug McCune, and Brandon Purcell have already posted great introductions to SpatialKey, so [...]
A week or so back I wrote about a package I ported/modified to create the Delaunay triangulation in Flash with a few AS3 classes. As I noted there, such a triangulated irregular network (TIN) allows us to interpolate isolines — lines of constant value (aka isarithms, commonly called contours).
So, given a field of points [...]
The term “heat map” has become increasingly confused. Perhaps it doesn’t matter, but for the record the above map is a choropleth map. It’s been branded by Google (as one of the Google Gadgets) with the sexier label “heat map”, and this (mis)usage is catching on. The term heat map is already [...]
I study cartogram design. Cartograms are thematic maps in which the enumeration units (states, countries) are resized based on a particular attribute (population, carbon emissions). There are dozens of types/designs of cartogram and many methods/algorithms for cartogram production.
These have gotten a lot of attention lately (uses the Gastner-Newman diffusion-based algorithm).
Some cartographers manually [...]
Choropleth maps, like the one above, use the visual variable of value (aka shade or lightness), sometimes in concert with hue or saturation, to present data about featues. Academic cartographers teach that this symbology should only be used in certain circumstances.
The phenomenon being mapped must be thought to vary only between enumeration units, and [...]