Composition Plots
Composition plots are ideal if you think about something as a part of a whole. For static
data, you can use pie charts, stacked bar charts, or Venn diagrams. Pie charts or donut
charts help show proportions and percentages for groups. If you need an additional
dimension, stacked bar charts are great. Venn diagrams are the best way to visualize
overlapping groups, where each group is represented by a circle. For data that changes
over time, you can use either stacked bar charts or stacked area charts.
Pie Chart
Pie charts illustrate numerical proportions by dividing a circle into slices. Each arc
length represents a proportion of a category. The full circle equates to 100%. For
humans, it is easier to compare bars than arc lengths; therefore, it is recommended to
use bar charts or stacked bar charts the majority of the time.
Use
To compare items that are part of a whole.
Stacked Bar Chart
Stacked bar charts are used to show how a category is divided into subcategories
and the proportion of the subcategory in comparison to the overall category. You can
either compare total amounts across each bar or show a percentage of each group. The
latter is also referred to as a 100% stacked bar chart and makes it easier to see relative
differences between quantities in each group.
Use
- To compare variables that can be divided into sub-variables
Stacked Area Chart
Stacked area charts show trends for part-of-a-whole relations. The values of several
groups are illustrated by stacking individual area charts on top of one another. It helps
to analyze both individual and overall trend information.
Use
To show trends for time series that are part of a whole.
Venn Diagram
Venn diagrams, also known as set diagrams, show all possible logical relations between
a finite collection of different sets. Each set is represented by a circle. The circle size
illustrates the importance of a group. The size of overlap represents the intersection
between multiple groups.
Use
To show overlaps for different sets
