Barplots

Barplots, or bar charts, are a type of plot that uses rectangular bars to compare data across categories. The length or height of each bar is proportional to the value it represents. They are commonly used to display counts, frequencies, proportions, or other numerical quantities on categorical data.

Barplots can be oriented vertically (bars rising from a baseline) or horizontally. The choice of orientation often depends on label length or available space. The simplest form shows a single series of data; more complex variants include stacked bar charts, where each bar is subdivided into segments representing subcategories, and grouped or clustered bar charts, where multiple bars are drawn side by side for each category to compare groups.

Critical design considerations include the baseline (often zero), the ordering of bars (by value, or in a meaningful category order), and the use of color, patterns, or labels to distinguish categories or groups. Legends should be used when multiple series are shown. Labels on bars or along axes improve readability. Accessibility concerns suggest avoiding color alone to convey information and providing descriptive titles and annotations.

Best practices include keeping the number of categories reasonable, avoiding misleading axis scales, and using consistent intervals. Barplots are not ideal for showing distributions of continuous data; histograms or dot plots may be more appropriate in such cases.

Barplots are widely supported in statistical and visualization tools, including R, Python's matplotlib and seaborn, Excel, and Google Sheets.