AAG Session: Geography on the Mac

Mapdiva is pleased to present the “Geography on the Mac” session at the 2011 Association of American Geographers (AAG) Annual Meeting in Seattle, WA on April 12-16.

Geography on the Mac is becoming an increasingly viable option in the geography curriculum as technologies continue to change and evolve. While Mac market share has been steadily on the rise, particularly among student bodies, the platform has historically been weak in supporting geography-related tool sets. That landscape is changing with new software being introduced and the opening of the platform to support the Windows operating system (OS). This session is designed to showcase a variety of geospatial Mac OS applications that are being used within the academic environment as integrated classroom research and learning tools.


  • Gaige B Paulsen, Using GIS for Crime Analysis on the Mac (Cartographica)
  • Kazimierz Zaniewski, Mapmaking with Cartes et Données
  • Larry Biehl, MultiSpec for Remote Sensing
  • Daniel Strebe, Introduction to Geocart 3 Map Projection Software
  • Jill Saligoe-Simmel, Introducing Map Design with Ortelius for Mac OS

Sponsored by the AAG Cartography Specialty Group.

Search and Select By Attributes Using Find and Advanced Find

Use Ortelius’ Find and Advanced Find toolbar to find and select features by their attribute information.

Find Objects

The Search Bar on the toolbar is used to find objects. Type in a search term and Ortelius will find and select any matching objects on the currently active layer. Objects are searched by default based on: 1. visible text, such as text boxes or labels, and 2. the “searchable text” of objects, which may include their attribute values.


For example, a simple search for “china” (note, not case-sensitive) quickly finds and selects the country from the active layer.



Operators available from a drop-down list are used to define the search.

Advanced Find


The drop-down menu on the Search Bar is used to open the Advanced Find window. Advanced Find presents a drop-down list of the fields that are available for searching. These include object and style properties, such as style name and any available attribute identifiers.

By default, the active layer is searched. As needed, check the option to search all layers. A search can be saved as a Smart Search for later use.


Hint: The “sounds similar to” operator finds text that sounds similar when pronounced in English – for example searching for “Fosfer” will find “Phosphor.” All other searches find an exact (but case-insensitive) match based on the actual characters.

Use Ortelius to Show a Buffer Around Map Features

Buffers are new polygons that represent an area of specified distance around another object. Buffers can help map readers visualize what other features are near or far from another feature. For example, you can create a 1-mile buffer around a road, or a 20-kilometer buffer around a river.

In Ortelius, Buffers can be quickly created around paths or tracks. Buffers can also be created around point symbol features, yielding a circular path of the buffer radius. Select the feature to be buffered. Choose Edit > Buffer from the main menu. A dialog appears. Enter the distance for the buffer (note that buffer distance is related to the scale of the drawing) and click OK. Buffer distance units will be displayed based on the View > Display Units setting in the main menu (points, page units, or map units). A new buffer polygon is created as a new map feature added to the currently active layer.

Buffers Can Be Styled Like Other Objects


To change a buffer polygon’s appearance, select it and choose a new fill style from the Symbols Palette. Alternatively, use the Colors Palette to drag-and-drop a color onto the buffer area. Semi-transparent fill styles without outline strokes work best for stylizing buffers. You can also create and layer multiple buffers by selecting the path or track again and entering a new buffer distance.