Comparing map projections
posted Thu 29 Oct 2015 by Michael Galloy under VisualizationFun site for map nerds or anyone trying to get a grasp on the differences between projections.
via Visualizing Data
Fun site for map nerds or anyone trying to get a grasp on the differences between projections.
via Visualizing Data
I linked to a great post on FlowingData a few weeks ago about some basic rules for visualizations. Nathan then gave a more detailed treatment of his first rule:
I already covered the small handful of rules that pertain mostly to traditional statistical graphics. The first oneâto always start your bar charts with a zero baselineâunexpectedly drew some disagreement, and I am unexpectedly compelled to go into more depth.
Great alternatives to a non-zero baseline.
There are a lot of suggestions for visualizations, but only a handful of actual rules.
Mike Bostock has created some really great visualizations of sampling, shuffling, sorting, and maze generation algorithms. He ends with a quick discussion of using vision to think, using his NYTimes interactive graphic âIs It Better to Rent or Buy?â as an example:
To fix this, we need to do more than output a single number. We need to show how the underlying system works. The new calculator therefore charts every variable and lets you quickly explore any variableâs effect by adjusting the associated slider.
via Flowing Data
Strava is a popular app for tracking your runs and rides. But the accumulated data that can be explored through the Strava Labs Global Heatmap is amazing! It is fun to look around and explore my areaâs use for rides and runs. (But, I could have told you that 4th St. was bike highway for people leaving town.)

Looks like Strava is now selling accumulated data to cities to help plan better bike routes. Portland is in.
via FlowingData
Not sure where I would ever use it, but I would love to be able to produce these xkcd-style plots in IDL, currently available in Javascript with d3, R, and Python with matplotlib.

An academic paper has been written about this and even provides a Processing implementation. From the abstract:
Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive.
So it appears that a plot that looks like a sketch indicates to viewers that it is not a âfinalâ product.
Datavisualization.ch is keeping a list of the tools that they âuse to create interactive and dynamic data visualizations:â
Thatâs why we have put together a selection of tools that we use the most and that we enjoy working with. We called it selection.datavisualization.ch. It includes libraries for plotting data on maps, frameworks for creating charts, graphs and diagrams and tools to simplify the handling of data. Even if youâre not into programming, youâll find applications that can be used without writing one single line of code. We will keep this list as a living repository and add / remove things as technology develops. We hope this will help you find the best tool for your next job.
I have mentioned many of these tools like ColorBrewer (many times), Processing, Processing.js, and Many Eyes.

Pathline is a visualization tool for genetic data created in collaboration between designers and geneticists:
We recently attended an interdisciplinary visualization workshop that was all about creating a dialogue between scientists, technologists and designers. It was interesting to discuss the different ways in which these groups think about visualization and how they use it for different purposes. Very bluntly put, each group lacks something another group knows and cares deeply about, be it an understanding of colour [we met in the UK] or an understanding of statistics.
The before and after images show a striking simplification that apparently helps even trained geneticists:
Two main advantages of the new tool were found. First, there was a massive gain in efficiency. The study of a heatmap took up to a half-hour before but can be done at a glance at the curvemap now. More importantly, though, the scientists made new discoveries of gene properties they didnât know about before. What was hidden in the data before, is now very clear, even to an untrained eye.
Iâve been catching up on Brian Hayesâ great âComputing Scienceâ column in American Scientist. The last issueâs âPixels or Perishâ discusses the move to interactive graphics from static print graphics:
Methods for producing scientific illustrationsâand for reproducing them in publicationsâhave been changing. Printing plates for figures were once engraved by hand, then made by a photographic process, and in recent years have been created by digital techniques. Now we are about to turn the pageâif not close the bookâon yet another chapter in publishing history. After centuries of reading and writing on paper, we seem to be headed for a world where most documents will be distributed online and viewed on a display screen of some kind. How will this transition to a new medium affect the practice of scientific illustration?
via FlowingData
NASA is hosting a series of challenges relating to pulling information from its collection of over 100 terabytes of data stored in its planetary data system (PDS):
But, while rich in depth and breath, the PDS databases have developed in a disparate fashion over the years with different architectures and formats for different scientific needs; thereby making acquisition of data problematic!
So, NASA is holding a series of Challenges to generate some simply awesome ideas for mobile or web based applications that will appeal to general users, to search and display compelling facts about the data. Instead of just scientists, our audience will be the millions of school age students, their teachers and parents, game designers and general civilians of the world. We want to deliver this incredible data to users in a way that excites them â and thus, to help them understand the value and potential of this data.
Prizes range from $500 to $10,000, as well as being named “Space Coder of the Galaxy 2012”. Some contests are restricted to teachers or high school students.
GPULib enables IDL developers to access the high-performance capabilities of modern NVIDIA graphics cards without knowledge of CUDA programming.
TaskDL is a task-farming solution for IDL designed for problems with loosely-coupled, parallel applications where no communication between nodes of a cluster is required.
mpiDL is a library of IDL bindings for Message Passing Interface (MPI) used for tightly-coupled parallel applications.
The Remote Data Toolkit is a library of IDL routines allowing for easy access to various scientific data in formats such as OPeNDAP, HDF 5, and netCDF.
Modern IDL offers IDL programmers one place to look, for beginners and advanced users alike. This book also contains: a thorough tutorial on the core topics of IDL; a comprehensive introduction to the object graphics system; common problems and gotchas with many examples; advanced topics not normally found are discussed throughout the book: regular expressions, object graphics, advanced widget programming, performance, object-oriented programming, etc.
IDLdoc is an open source utility for generating documentation from IDL source code and specially formatted comments.
mgunit is an open source unit testing framework for IDL.
rIDL is an open source IDL command line replacement.
mglib is an open source library of IDL routines in areas of visualization, application development, command line utilities, analysis, data access, etc.