Purpose – To create a thematic map that shows the percentage of vacant housing units, using pie charts to depict the percentage of vacant units to percentage of units as segments of the pie chart. The scale of each pie chart is in proportion to the population in each county within the State of Pennsylvania.

 

Method – The projected coordinates were set to Contiguous Albers Equal Area Conic for the cartographic boundary file and corresponding attribute data from the United States Census Bureau.

 

Each county polygon was then converted to point data. Within the attribute table, a new field was created for the calculation of vacant units and the percentage of units vacant. Within the symbology tab, charts were selected as the map type and pie was selected as the type of chart.

 

Using the newly created attribute fields of vacant units and percentage of units as the field selections. To add spatial pattern and magnitude to the pie charts, the Population 2000 field was selected within the attribute table and symbol size to 30 points.

 

The pie chart symbology used CMYK colour values of the same hue for each segment. Values of small, medium and large populations were selected within the range of population values in the Population 2000 field of the attribute table and rounded off.