Thematic Maps and Map Projection Utilities
A thematic map displays the spatial distribution of an attribute relating to specific data themes (e.g., population density, skin cancer mortality rates, rainfall, soil type, median age, number of housing units, pollutants concentration in air, etc.). Thematic maps provide specific information about particular locations.
Aabel allows creating thematic map diagrams that can display spatial data interactively using different options and easy to use customizing tools, and includes several importers as well as map projection utilities.
Thematic Map DiagramsAabel allows plotting polygon thematic maps, polygon point frequency thematic maps, and polyline diagrams. Polygon thematic maps: Allowing display of the associated data by:
Polygon point frequency thematic maps: Displaying data point frequency of X-Y coordinate pairs that represent occurrences of an item in different locations (see bottom images below). |
Importing CapabilitiesPolygon and shape file data sets are readily available for download in the public domain. To enable importing and arranging polygon data, or defining the data using different projection systems, Aabel provides importers for:
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Creating a Thematic Group OverlayCombining a thematic map and one of the following charts can create a thematic group:
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Displaying Polygon Center PointsYou can choose to display the center point of each polygon on a base map.
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When creating a thematic group, the X-Y coordinates of the chart and the base map polygons must have the same projection system and data units. If your data require transformation, you can use the map projection utilities built into Aabel worksheets.
QuickTime Movies of How to Create Thematic Maps in Aabel
Creating a Polygon Frequency Thematic Map Time: 00.00:18 |
Displaying Spatial Data Dynamically Time: 00.00:19 |
Creating a Thematic Group Overlay Time: 00.01:57 |
Operating on Selected Polygons
- Aabel viewers provide capabilities for:
- Generating subsets of data from selected polygons
- Removing selected polygons from a map (see the image below)
- Aabel worksheets provide capabilities for initializing or changing projection system for either a coordinate pair or any number of selected variables.

Integrated Map Projection Utilities
If the polygons are imported as numeric data with no explicit sample space, cartographic coordinate transformations are required to store the data as longitude-latitude or to define them using a different projection system. Aabel provides map projection utilities built into its worksheets to allow the following transformations:
- Forward projections, which represent transformation of the spherical longitude-latitude coordinate system of the earth to the X-Y coordinate system of paper
- Inverse projections, which allow you to transform the initially projected coordinates back to longitude and latitude
Aabel includes 19 projection systems, the geographic coordinate system, and the state plane coordinate system.
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The state plane coordinate system is specific to US, and once a zone and the datum are selected, Aabel will automatically use the state-legislated projection and unit for that zone, as defined in NAD27 and NAD83. |
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