Tuesday, March 30, 2010

Tuesday Tools: Map Symbol Brewer

What is Map Symbol Brewer?

The development of the Map Symbol Brewer tool was part of Olaf Schabel's PhD Thesis at the Institue of Cartography in Zurich, Switzerland. The goal of the project was to create a tool that would allow for the easy visualization of statistical data with map symbols. Other tools, such as the data-graphic environment SageTools, had already existed that could automatically generate map symbols. However, Map Symbol Brewer aims to generate customized map symbols using a step by step process that is based on the data that is input and the needs of the user. The final product is an online application that generates complex user-defined map symbols that can be used in interactive map applications.


The Map Symbol Brewer tool uses the idea of primitives in map symbols. Primitives are basic shapes for map symbols and include ellipses, symmetric polygons, and pie sectors. From these basic shapes, the following simple map symbols can be generated.

Data values are used to construct and scale these primitives.  For example, bigger data values generate bigger symbols.  In addition to primitives there are diagrams, which are used for symbols that need to represent multiple data values. Diagrams can follow eight different arrangement principles as shown in the following table developed by Schabel :

Using the Map Symbol Brewer Application

To use the Map Symbol Brewer application, visit the website. You can either upload your own data or use the European map and test data provided. If you are having trouble uploading files, read how to structure your upload files.  Once the data is uploaded, you can generate the map symbol description by developing the DiaML (Diagram Markup Language) file.

DiaML Generation and Map Export

DiaML generation is a step by step process that is separated by tabs to the right of the preview map. First, you choose the type of the symbol you'd like to use. The options are a simple symbol for one data value or a diagram for multiple data values.  On the following tabs, you choose a primitive and set the primitive attributes, define their arrangement, and select the color scheme. In the fifth tab, you select guides for the map symbols or add an interactive component to the symbols. Finally, in the sixth step, you can export the map as a DiaML file in .xml format or as an SVG file.

In Schnabel's report on the Map Symbol Brewer, you can also find some example outputs of his prototype, such as the following:

Monday, March 29, 2010

Miscellaneous Monday: 2010 Census Participation Rates

As many people have recently discovered, the United States Census Bureau is currently working to complete its decennial, Constitutional obligation of a complete population count. To get an even higher response than in previous years, the U.S. Census Bureau has streamlined their questionnaire, increased awareness, and made the whole process generally more bearable. Starting in mid-March, the simple “10 questions in 10 minutes” census questionnaires were mailed out to every household in the United States and Puerto Rico. Almost immediately the responses started rolling in.

To keep the general public interested and updated as to the status of their hometown, state, or the country as a whole, the U.S. Census Bureau created a fun online map depicting the “Mail Participation rate” or the percentage of homes that received questionnaires and mailed back responses. As of this posting, participation rates are generally in the mid-20’s to low 30’s, with several states actually reaching as high as the low 40’s.  Houston, however, is falling behind. With the national average at 34%, the city is more than 10 percentage points behind, with a participation rate of 21% and Harris County is doing only slightly better with participation at 23%. This is a great improvement from last week’s numbers, which, as reported in a Houston Chronicle article, had Houston 20% behind the national participation average.

With just one week to go (forms are due on April 1), hopefully Houston and the rest of the country will turn in their forms. The U.S. Census Bureau actually estimates that if every household in the country returns their forms it will save the government $1.5 billion dollars.  Everyone should do his or her part to provide accurate and timely responses, which will not only save the government money, but also help determine how and where the government spends its more than $400 billion annual budget. For more information on the 2010 Census visit the U.S. Census Bureau’s homepage.

Friday, March 26, 2010

Fun Friday: geoGreeting

geoGreeting is a fun way for you to send your friends short greetings from the surface of the Earth! Jesse Vig, the site's creator, noticed, while working in Google Maps, that certain buildings looked like letters from above.

Visit geoGreetings to create and share your own greetings.

Click on the provided link to view a special GDC message! (If the animation does not load, you can view a still shot here.)

Thursday, March 25, 2010

Thursday Data: Map Library

Map Library is a data source project of the Map Maker Trust that is devoted to providing free “basic map data concerning administrative boundaries in developing countries” for any public user. Currently, the project is limited to maps of countries in Africa and Central America, but the available data is still quite elaborate. Once you have selected the region and country you desire, a list of all the available data will open. You can then download various files, including administrative areas and satellite images in either a latitude and longitude coordinate system or in the Universal Transverse Mercator (UTM) coordinate system. The available files come in three or four formats (depending on the country and coordinate system) including shapefiles for ArcGIS use, KMZ files to be used in GoogleEarth, Map Maker DRA format, and MapInfo MIF format.

The Map Maker Trust, creator of the Map Library project, provides access to more than just maps. Currently, the charity's website is hosting version 0.9 of the Global Administrative Areas (GADM) database of the BioGeoMancer project. GADM, as discussed in our Dec. 10 blog, “is a database of the location of the world's administrative areas. Administrative areas in this database are countries and lower level subdivisions such as provinces, departments, districts etc.” Again, this data is available in a number of formats (shapefile, Map Maker DRA, and MapInfo MIF format) and is provided in a  latitude and longitude coordinate system. Additionally, the Map Maker Trust provides access to free software tools that can be used to easily display and manipulate map data. To get a look at some of the software that is available, as well as some external links to mapping data, visit The Map Maker Trust.

Below is a look at some of the data that the Map Library project has to offer.

Wednesday, March 24, 2010

Web Wednesday: DIY Map

DIY Map is best described as “a clickable, zooming map written in Flash and colored by data from an external text file.” Creator, John Emerson, established this online system to enable any individual to create interactive maps for their personal use. Emerson provides detailed instructions on how to complete each and every step of the map production process.

Simply download the desired map and unzip the archive (you have the choice of using a map of the entire world, U.S., U.S. and Canada, Australia, Belgium, Brazil, Canada, Europe, France, Germany, Italy, Mexico, The Netherlands, Sweden, or U.K. and Ireland). From here you have a number of choices from adding additional city coordinates (the site provides a number of helpful links) to using the "preview a demo" link to give examples of the different uses for DIY maps.  Alternatively, you can simply jump right in to editing the XML code of the data file to your personal preferences. To understand the language used in the XML data file and for information on how to accurately edit each and every line of the code visit the Configure page. Finally, after you are completely done editing the data file, you can embed your newly created map file into your personal webpage using the Embed the Flash file help link.

Below are some still images and links to the original clickable DIY maps that the site uses as preview demos, displaying the uses for some of the standard data files that the site has to offer.

For more information on this presidential election map, including the source and fully coded data file, visit the U.S. examples page and scroll down to the fourth map.

For more information on this global unemployment map visit the World examples page and scrolls down to the third map.

Visit the DIY home page to click around this map of recent visitors to the DIY Maps website.

Tuesday, March 23, 2010

Tuesday Tools: Export To CAD

The ArcToolbox application for ArcGIS contains countless little known tools that can be extremely helpful in data manipulation, general visualization, and analysis. One such tool is "Export to CAD", which is now available under the ArcView license. (Prior to ArcGIS 9.3, the tool required the ArcInfo license, making it unavailable to many users.)  If you are interested in learning how to export your GIS data into a native CAD format, follow the directions outlined below.
  1. Click on the ArcToolbox icon.
  2. Double-click on Conversion Tools --> To CAD and double-click on the Export to CAD tool.
  3. From the Input Feature drop down menu, select your input file. From the Output Type drop down menu, select your desired CAD file type. Under Output File, input your file destination and name.
  4. Click OK.
It is important to note that, when exporting documents into CAD, most of the attributes associated with your data may be lost. In the case of an export of contour lines, you will lose elevation information, colors, and labels, retaining only the physical lines themselves. There are a variety of ArcToolbox tools within the “To CAD” toolset that may help with the retention of such information. Visit the ESRI help page for more information and assistance using these tools.

Monday, March 22, 2010

Miscellaneous Monday: Geo-Volunteerism

The way Google now keeps its maps current and up to date offers an interesting insight into the state of the mapping industry. Previously, Google employed Tele Atlas, one of the digital mapping giants dominating the industry, to maintain their U.S. maps. However, in October 2009, Google dropped Tele Atlas and began relying more heavily on government data and contributions from "citizen cartographers" or "geo-volunteers". These are people, equipped with GPS devices, who create new digital maps, or fix mistakes and add information to existing online maps. Tweaking the location of businesses and other destinations is a common activity among citizen cartographers. And this hobby is not exclusive to just a few dedicated enthusiasts. In Atlanta, there was a three day Citywide Mapathon in which community groups joined forces to gather data for the creation of a map with a complete list of points of interest and local destinations.

Many people view this shift as a positive one, because they believe local people are bound to know their communities more intimately and are better equipped to deliver correct map information. There is also technology available now that gives the "everyman" the power to do what was once reserved for professionals and specialists. There are smart phones with GPS capabilities, such as the Waze driver generated mapping system. The Waze platform, pictured to the right, works on a smartphone and sends anonymous information back to you such as location and speed, and allows you to report on your travels. The way the system is set up, the more users that work with Waze, the more accurate the information will be.

Also, there are web tools, such as OpenStreetMap.org, Wikimapia, and now, Google Map Maker that are making it possible to create annotated maps that are open to the public for editing.

However, this new trend is not without its skeptics. While many people believe that the new publicly edited maps are just as accurate as traditional maps, the VP of global engineering at Tele Atlas insists that there is still a need for the due diligence and quality that professional map making firms provide. While they are integrating information from citizen cartographers into their maps, they believe that when it comes to emergency vehicle access or delivery routes, people need to be able to rely on professional map makers. He analogizes by saying that, Wikipedia, despite being a very interesting information source,  is not a creditable source that historians will use to defend their theses. Furthermore, there is an inherent political characteristic of maps, especially in areas of land dispute. While professional map makers don't completely eliminate the politicization of maps, they can aim to treat certain areas with sensitivity. An open, anonymous system of editing is much more conducive to the creation of controversial maps.

In the end, it seems that the industry is currently being served by utilizing traditional, professionally gathered map data while still valuing the information that is contributed by local citizens.