Showing change on a map
The static maps that were described in an earlier chapter can also be turned into dynamic diagrams if they are displayed on a computer.
Calorie intake in Africa
The circles on the African map below show the populations of the countries (circle areas) and the average calorie intake (Kcal/capita/day) in each country.
The initial display shows clearly the regions in which food calorie intake was highest (blue) and lowest (yellow) in 1990. Drag the slider to see how this changed between 1990 and 2005. Observe in particular:
Rural and urban population in Africa
The next diagram is similar, but shows the rural and urban population in each country as a pie chart.
Again drag the slider to see the urbanisation of Africa between 1950 and 2005.