Interesting Tool of the Week: Quadrigam – Connecting two visualizers
Aug 18th, 2015 by Tom Johnson

Take me to Quadrigam

Connect two visualizers

All of the charts have input data and output data. You can synchronize two charts just using the output data element of the first chart as the input data element of the second chart. You can even build formulas based on data outputs, like for instance using the element selected in a control list to be part of a formula which filters a given datasset based on one column which elements match with the selected element in the control list. Charts use to have two main data outputs:

  • On over: When on over with the mouse, the element will be the data output of that chart.
  • Selection: When clicking on a given element of a chart (e.g: a serie in a Line chart) that will be the output element that can be synchronize with another chart. In Maps, we also have “zoom” and “center” which make super easy to syncrhonize, for instance, two maps (the zoom and center of the first map act as input data elements of the second map).
The Guardian view on geography: it’s the must-have A-level
Aug 13th, 2015 by Tom Johnson

It used to be a Cinderella subject. Now, in a world that increasingly values people who can work across the physical and social sciences, geography’s all the rage

Aerial view of Surfers Paradise, Australia
 ‘Geographers learn about the physics of climate change, or the interaction of weather events and flood risk, or the way people’s behaviour is influenced by the space around them.’ Above, Surfers Paradise, on the Gold Coast, Australia. Photograph: Chris Hyde/Getty Images

A star is born. Geography, for so long a Cinderella subject, the easy option for students who found physics or chemistry too daunting, is soaring in popularity. According to the Royal Geographical Society, 13% more took the subject at A-level this year than last, up to 37,100 – the biggest jump of any of the major subjects.

Part of the explanation is Michael Gove’s determination to make schools focus on more traditional academic subjects at GCSE and A-level, rather than general studies or critical thinking. That is good for those who can benefit from a narrower academic focus, but not so much for those who struggle. It may be, however, that the bigger reason is that geography is a subject for our times. It is inherently multidisciplinary in a world that increasingly values people who have the skills needed to work across the physical and social sciences. Geographers get to learn data analysis, and to read Robert Macfarlane. They learn geographic information systems. They can turn maps from a two-dimensional representation of a country’s physical contours into a tool that illustrates social attributes or attitudes: not just where people live, but how, what they think and how they vote. They learn about the physics of climate change, or the interaction of weather events and flood risk, or the way people’s behaviour is influenced by the space around them.

All these are not just intrinsically interesting and valuable. They also encourage ways of seeing and thinking that make geographers eminently employable, which is why, according to the latest information from the Higher Education Careers Services Unit, only 5.8% of geography graduates were still job-hunting six months after they graduated, against an average of 7.3%. So, year 9, globalisation: good or bad? And for whom?

IRE, Esri partner to offer fellowships for mapping training
May 12th, 2015 by Tom Johnson

IRE and Esri have partnered to offer fellowships to attend mapping training at the 2015 Esri Conference from July 18-22 in San Diego or the IRE Mapping Boot Camp from August 7-9 at the University of Missouri-Columbia, Mo.

The Esri Conference fellowships cover airfare and four nights lodging, and the Boot Camp fellowships cover airfare and three nights lodging. The Esri Conference schedule includes attendance at the following events: Esri Business Summit (July 18-19) to learn about how international businesses are using advanced mapping technology: Conference Plenary Session (July 20); and hands-on training for journalists. The application deadline is May 14. Apply now!

Tracking campaign contributions with MapLight
Jun 19th, 2014 by Tom Johnson

Maplight, a 501(c)(3) foundation, recently announced its “extensive mapping project examining the geographic origin of contributions to legislators by state; contributions from companies to legislators by state; and roll call votes by state and district on key bills in Congress.”

Today’s news peg points to “Who in Your State Has Contributed Money to Majority Leader Candidate Kevin McCarthy (R-CA)?”

MapLight looks to be a good edition to our GIS toolbox.

MOOC from Penn State: Maps and the Geospatical Revolution
Apr 7th, 2014 by Tom Johnson

A free MOOC on GIS and spacial analysis will be offered by Pennsylvania State University starting 30 April 2014. 

The course link and description:

Maps and the Geospatial Revolution
Learn how advances in geospatial technology and analytical methods have changed how we do everything, and discover how to make maps and analyze geographic patterns using the latest tools.

About the Course

The past decade has seen an explosion of new mechanisms for understanding and using location information in widely-accessible technologies. This Geospatial Revolution has resulted in the development of consumer GPS tools, interactive web maps, and location-aware mobile devices. These radical advances are making it possible for people from all walks of life to use, collect, and understand spatial information like never before.

This course brings together core concepts in cartography, geographic information systems, and spatial thinking with real-world examples to provide the fundamentals necessary to engage with Geography beyond the surface-level. We will explore what makes spatial information special, how spatial data is created, how spatial analysis is conducted, and how to design maps so that they’re effective at telling the stories we wish to share. To gain experience using this knowledge, we will work with the latest mapping and analysis software to explore geographic problems.

David Rumsey Map Collection adds 1,634 new maps
Mar 19th, 2011 by Tom Johnson

From Rumsey's site:

1,634  new maps and images have been added to the David Rumsey Map Collection, bringing the online collection to over 26,000 maps and images. Included in this addition are five issues of Colton's General Atlas of the World dated from 1865 to 1886. Also two editions of Schonberg's Standard Atlas of the World, 1865 and 1867. Sheets from two national surveys: six composite images of the entire Wheeler Survey of the U.S. West, 1876, and the first 338 sheets of the massive 19th century survey of Germany, Karte des Deutschen Reiches, 1893 (the remaining 336 sheets will follow in the next update). Added are elegant maps from the Atlante Geographico de Agostini, 1952, and a complete set of all the Shell Oil Company Automobile Road maps of North America, 1956. All titles may be found by clicking on the View links or images below. Or click here to view all 1,634 new maps and images.


Race and ethnicity mapped by block
Sep 20th, 2010 by Tom Johnson

Census tract data and maps, while better than nothing, can often deceive because the size of the tract is greatly influenced by population size, not area. It is not uncommon that natural and constructed barriers — mountains or freeways — influence the movements and spatial demographics of a tract. Ah, but BLOCK data, now there is some fine, fine-grained data that we can use to extract insights and meaning.
Once again, tips us off to a good visualization of population data and the resulting maps.


Race and ethnicity mapped by block

Sep 20, 2010 to Mapping | Post on Twitter

A taxonomy of transitions

Instead of breaking up demographics by defined boundaries, Bill Rankin uses dots to show the more subtle changes across neighborhoods in a map of Chicago using block-specific data US Census.

Any city-dweller knows that most neighborhoods don't have stark boundaries. Yet on maps, neighborhoods are almost always drawn as perfectly bounded areas, miniature territorial states of ethnicity or class. This is especially true for Chicago, where the delimitation of Chicago's official “community areas” in the 1920s was one of the hallmarks of the famous Chicago School of urban sociology.

Each dot represents 25 people of the map color's corresponding ethnicity.

Eric Fischer takes the next step and applies the same method to forty major cities. Here are the maps for Los Angeles, San Francisco, and New York, respectively. Same color-coding applies. You definitely see the separation, but zoom and you much more subtle transitions.

[Eric Fischer via Data Pointed]

Taking control of Google Maps
Sep 8th, 2010 by Tom Johnson

Patrick Cain, who correctly describes himself as “a journalist who makes maps for the Web,” has posted a couple neat sets of tips to his blog. Basically, they suggest ways to tweak some of Google's code to improve presentation. Check out his blog tips at


Simplifying map display

I’ve never been a fan of the way Google Maps handles local labels (neighbourhoods, for example) – they are often redundant, inconsistent and wrong, as well as cluttering the map visually.

These examples didn’t take long to collect:

Leslieville is so nice they labeled it twice:

Same with the Bridle Path, more or less:

Google has solved the unresolvable Beach vs. Beaches debate by using both labels:

Forest Hill South is not an ambition of well-off Annexites, but is actually north of Forest Hill:

WSJ goes the distance with the Google Maps API
Aug 10th, 2010 by Tom Johnson

A good piece on the  on how the Wall Street Journal crew created a fine set of maps illustrating various major-city marathons.  Go here for complete piece.

WSJ goes the distance with the Google Maps API

Sunday, August 08, 2010

The following guest blog post was written by Albert Sun of the Wall Street Journal. He takes us behind the scenes in the creation of a recent news graphic titled: “Going the Distance: Comparing Marathons“.

The Google Maps API has been a great boon for news websites and a great help in creating all kinds of interactive graphics involving maps. Here at the WSJ we're big fans of the API and happy that Google continues to improve it and roll out new features.

 We got the idea to map out the routes of Marathons from a story by Kevin Helliker about how despite the beautiful scenic route of the race, the San Francisco marathon was still very unpopular. The difficulty and the hilly terrain kept people from attempting it. To help people see this better, we decided to compare the San Francisco marathon to the big three US marathons: Boston, New York and Chicago.

The code for our marathons graphic grew out of a similar graphic we did for our coverage of the Tour De France. In this one, we managed to incorporate many improvements. Two new features of the Google Maps API played a big role in this graphic. The Elevation API let us quickly and easily get a comparison between the different routes.

Styled Maps let us give the map more of a distinctive WSJ look. We have a distinctive style for our maps in print, and there is some reluctance to run maps online that deviate from that style. Styled Maps lets us get close enough for what we're trying to show. When Styled Maps first becomes available we used the Styled Map Wizard to create a set of different looks for different types of maps, trying to recreate our own maps style.

Along with the Google Maps API, we used jQuery for its wealth of convenience functions and how much easier it makes writing programs in JavaScript. The core of the graphic is a basic Polyline drawn in Google Maps showing the route.  [more]


Use "BatchGeo" to quickly generate Google Maps with multiple locations
Jun 19th, 2010 by Tom Johnson

If you've acquired a spreadsheet file with a bunch of addresses, you can quickly map them using BatchGeo.  We haven't tried it yet with a huge data set, but it works nicely with a couple hundred addresses.  Check out BatchGeo at

Have locations in a spreadsheet? Well try this free and unique tool to…

  • Map them using Google Maps
  • Publish a map on your Web site
  • Create a store locator
  • Get coordinates, print maps, and more!

Get started by following the steps below, or check out our video tutorials

What could I use this for?

  • Create a map – Copy directly from spreadsheet program such as Excel, Numbers, or the free Google Docs or OpenOffice Calc.
  • Distance Calculator – Calculate the distance in miles or kilometers to several locations from a single address.
  • Satellite Photos – Addresses are linked to Google Maps for satellite photos and driving directions.
  • Make your own Google Earth KML – Quickly create KML files with your address data for 3D viewing data in Google Earth.
  • Get postal codes / zip codes – Retrieve postal or zip codes for a given address internationally.
  • Print a map – Make a printable map with your addresses on it.
  • Save a map – Create a map with your locations and associated data to a web page for later use.
  • Create a store locator – Map your store properties, and then link to them from your website.
  • Get center coordinates (centroids) for a listing of zip codes, cities, or states.
  • For quick single address geocodes, zip code, city or state centroids use our Single Address Lookup Tool ”

»  Substance:WordPress   »  Style:Ahren Ahimsa