Posts Tagged ‘projections’

Review of new tome for map projections: Lining Up Data in ArcGIS (Vector One)

Thursday, June 24th, 2010

lining-up-data-sm[Editor's note: No PRJ file? No problem. Use this new guide by M. Maher from ESRI Press to learn map projection basics and the ArcGIS commands (versions 9 and 10) that register map data to common coordinate spaces. Read the first chapter and table of contents at ESRI.]

Republished from Vector One.

Lining Up Data in ArcGIS – a guide to map projections is a new book from ESRI Press. It is authored by Margaret M. Maher. Since I don’t have ArcGIS running in my office I couldn’t try out some of the details provided in the book, nevertheless, I did spend some time running through the book and offer the following comments.

One of the issues that many people encounter with GIS data revolves around projections, coordinates and lining up data with already existing spatial information. I’ve made the mistake myself numerous times, excited to get the data into the system, only to open the map window and finding what I just added from Berlin is placed in Oklahoma, Alberta or the middle of the Mediterranean Sea. How did that happen? Because I never lined up the data properly.

This book is very helpful. It explains how to identify geographic coordinate systems as compared to projected coordinate systems. If you are using ArcMap, then this book will show exactly how to determinine projections and set them. It even provides examples for going to ArcGIS Online, downloading imagery and aligning it properly.

Continue reading at Vector One . . .

News Dots (Slate)

Wednesday, September 9th, 2009

slatenewsdots

[Editor's note: This is one of the first tools I've seen that links topics, people & places into a network of graduated circles based on their ranking in the news. The circles are arranged based on their edge connections within the overall topology using the Flare visualization package in Flash AS3. As seen in the above screenshot, Germany is linked to Afghanistan, NATO, the Taliban, The Washington Post, and 20 other nodes. This project is one step forward in the vision I outlined in Topology and Projections: 21st Century Cartography. Disclosure: Slate is owned by the Washington Post Company, my employer, but I was not involved in this project.]

Republished from Slate.

Introducing News DotsAn interactive map of how every story in the news is related, updated daily.

Like Kevin Bacon’s co-stars, topics in the news are all connected by degrees of separation. To examine how every story fits together, News Dots visualizes the most recent topics in the news as a giant social network. Subjects—represented by the circles below—are connected to one another if they appear together in at least two stories, and the size of the dot is proportional to the total number of times the subject is mentioned.

Like a human social network, the news tends to cluster around popular topics. One clump of dots might relate to a flavor-of-the-week tabloid story (the Jaycee Dugard kidnapping) while another might center on Afghanistan, Iraq, and the military. Most stories are more closely related that you think. The Dugard kidnapping, for example, connects to California Gov. Arnold Schwarzenegger, who connects to the White House, which connects to Afghanistan.

To use this interactive tool, just click on a circle to see which stories mention that topic and which other topics it connects to in the network. You can use the magnifying glass icons to zoom in and out. You can also drag the dots around if they overlap. A more detailed description of how News Dots works is available below the graphic.

Interact with the original and learn more at Slate . . .