
158 Web Cartography: Map Design for Interactive and Mobile Devices
The main thing to remember when designing proportional symbols is that
you must size the symbols proportionately based on area, not radius, cir-
cumference, width, height, or any other form of measurement. If you do not
make your symbols proportionate by area, you will end up with massively
distorted sizes that grossly embellish differences in values.
The difference between proportional and graduated symbols is quite
simple. Proportional symbols are sized proportionately to the other val-
ues in the dataset (see Figure9.11). Thus, the symbol representing Bavaria
Mecklenburg-
Vo