GEOG 361, C. Brewer

Proportional Symbols
Readings: Chapter 17 in Slocum

Examples from Census atlas: Total Population

Proportioned to counts (totals)
proportioned squares, count 

Proportioned to rates
 proportioned circles, rate   proportioned bars, rate  Linear symbolschoroopleth, count data Choropleth of rates

Basic calculations for linear, area, and volume symbols...practice

Proportioned vs. graduated symbols
proportioned circles, count  graduated circles, redundant fill  choropleth, count data  corresponding choropleth (Graduated color)

Examples from article in Cartographic Perspectives (Winter 98)

Symbols that compare related amounts:

Symbols that show proportions (segments of a whole):


3D examples for comparison and proportions:


Sizing and legend tips

Protate cancer map

convert legend to graphics     ungroup graphics