Esri Mapping Center - Ask a Cartographer

Map symbol brewer

October 22 2009 | 1 comment
Categories: Cartographic Design

Does ESRI have any developments afoot to implement a more comprehensive set of graphical symbols than the currently limited spot, pie and bar? I am thinking on the lines of the work of Dr. Olaf Schnabel, who developed the Map Symbol Brewer (http://www.oschnabel.gmxhome.de/portfolio_en.html). This kind of development would make ArcGIS a useful tool for summarising multivariate point data on a map, and would save users a great deal of time in developing their own shaky scripts to draw things like Maucha, spider, polar and radar diagrams.

The proxy server did not allow an upload to the ESRI site, but an example of what I am asking is at this link: http://www.dwaf.gov.za/iwqs/water_quality/NCMP/natl_assmnt04_maucha.pdf.

The R statistics program has many of these types of symbols, and has a simple mapping procedure for shape files (and it's free). However, the ideal would be to use the symbols in a cartographic environment.

Mapping Center Answer:

There's no effort like this afoot. Once you start digging, there is no such thing as a comprehensive list of graphical symbols--there is no practical limit to what could be symbolized.

The problem of multivariate thematic symbology for maps is challenging, not just to make the map, but to read it as well. Back when all we had was paper, relatively few of these maps got made, but those that did were usually pretty decently designed and executed (meaning expensive). In the digital mapping age, if the will exists to make such a map, it can be done, but because these are all specialty maps, they are on the fringe of most people's expertise, so finding a cartographer is a challenge, and it's, like you indicate, a lot of work.

We are not limited to paper any longer, but because such maps are not mainstream, you're just not likely to see a generic or mainstream tool for making them. But web maps are offering some solutions, particularly by leverating Web 2.0 graphics engines against GIS services. For instance:

http://downloads2.esri.com/mappingcenter2007/maps/worldtopomap/ESRI_demographics_Ex.html

Where instead of using a complex symbol for every polygon, symbology is based on a characteristic that explains something commonly understood, and then clicking on that feature gives better context. I'm not saying this replaces the need for rich multivariate symbology, but it offers an alternative that will work well in many cases.

Star and rose map symbols posted by Michael Silberbauer on Nov 3 2009 5:25AM

The ESRI demographics example is very elegant mentioned above, and neatly solves the problem of allowing the interested user to view the detailed information available for a region of interest. However, this differs from the problem that faces people working with water quality data, which is to show multiple variables for many sites scattered across a map. This need not be confusing, so long as one uses common-sense visualisation to avoid confusion, as suggested by authors such as Ware, MacEachren or Slocum. The background map can display other information without distracting attention, for example rivers as lines and land use as polygons.

An example is the use of KML to display monitoring points symbolised with ionic composition Maucha diagrams on a 3D-earth backgound. The user can click on an interesting site to bring up a balloon with metadata, and follow other links in the balloon to see the time series data (see http://www.dwaf.gov.za/iwqs/wms/data/000key.asp). The ability to 'splay' overlapping points when they are selected is essential.

However, to return to the original question about development plans, which was prompted by Olaf Schnabel's contention that, despite the phenomenal developments in spatial analysis software during the past couple of decades, the encoding of multivariate statistics on maps has actually decreased. His thesis suggests a way of overcoming the substantial programming difficulties by standardising the process of generating symbols using a diagram markup language as demonstrated in his Map Symbol Brewer.

My own experience with developing multivariate symbols during the past 20 years supports the view that we have somehow hit a ceiling:

Pascal - generate the symbols, print them and glue them on a paper map
Arc Info - generate the symbols on the actual map with SHADE
ArcView - generate symbols as groups that can be shifted when they overlap
ArcGIS - generate symbols as groups that crash ArcGIS when you bring a mouse anywhere near them

GIS systems surely need to have more advanced symbolisation built in, so that users can concentrate on presenting their data rather than trying to encode concepts in ever more obscure and user-hostile computer languages. Any GIS package that offers more multivariate symbol options than the run-of-the-mill pub lunch (bar and pie) will have an immediate competitive advantage.

Here are a few references on the subject:

Schnabel O. Benutzerdefinierte Diagramm-signaturen in Karten: Konzepte, Formalisierung und Implementation. Eidgenössischen Technischen Hochschule Zürich; 2007. Available from:http://e-collection.ethbib.ethz.ch/eserv/eth:29352/eth-29352-01.pdf. A paper in English on the subject is: Schnabel O, Hurni L. Primitive-based Construction Theory for Diagrams in Thematic Maps. Cartographic Journal. 2009;46(2):136-145. Available from:http://dx.doi.org/http://dx.doi.org/10.1179/000870409X459851.

Tufte E. (assorted)

Ware C. Visual Thinking: for Design (Morgan Kaufmann Series in Interactive Technologies)

Slocum T A, Mcmaster R B, Kessler F C, Howard H H. Thematic Cartography and Geovisualization.

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