Violin plot
Definition
Method of plotting the distribution of numeric data combining KDE plots and box plots
Anatomy
The violin plot is a statistical visualization derived from the kernel density plot. In its typical form, the violin plot consists of a central box representing the quartiles and of a rotated kernel density plot on each side showing the full distribution shape.
Interpreting a Violin Plot
In a violin plot, the following elements are key to interpretation:
- The width of the “violin” at any point represents the estimated frequency of data points at that value.
- The interquartile range is usually represented as a thick bar in the middle
When and How to Use a Violin Plot
Strengths
- Provides a rather complete view of one or multiple data distributions
- Allows comparison across multiple groups
- More informative than standard box plots
- Reveals multimodal distributions
- Works well with large datasets
Caveats and Limitations
- The density estimation used to create violin plots can be sensitive to binning and smoothing parameters, potentially leading to misleading interpretations
- For small datasets, the density estimation may be inaccurate, and altogether the violin plot will be less useful than an alternative showing individual data points
- Multi-category violin plots can become cluttered with too many categories
Recommendations
- Ensure the number of data points is high enough
- Consider combining it with other distribution visualizations
Links
Wikidata entity: Q7933383
Wikipedia page: Violin plot