distributionby

Distributionby is a term encountered in some data-analysis contexts to describe the distribution of a variable when data are partitioned by another variable. It is not a widely standardized term in statistics, and its exact meaning can vary by software and domain. In many cases, it functions as a shorthand for producing distributional summaries within subgroups defined by a by-variable.

In statistical practice, the closest formal concepts are conditional distributions and stratified distributions. These describe how the distribution of a variable changes when conditioned on or analyzed separately across levels of a second variable, such as computing P(Y|G) or distributions within each category of G. The idea behind “distributionby” aligns with reporting or visualizing these subgroup distributions rather than a single pooled distribution.

In software libraries, distributionby may refer to a feature or function that groups data by a key and returns distributional summaries for each group. Such functionality typically supports producing histograms, density estimates, quantiles, or category proportions within every group, enabling comparative analysis across groups. The exact interface, performance considerations, and supported distribution metrics depend on the implementation.

Common use cases include comparing distributions of a variable across demographic groups, regions, time periods, or treatment conditions. Practical considerations include choice of bins or metrics, handling of missing values, and scalability to large datasets.

See also: groupby, conditional distribution, stratified analysis, descriptive statistics.