Frequency Trails

Frequency trails: mean butterfly plot

Frequency trails are a simple and intuitive visualization of the distribution of sampled data. I developed them to study the finer details of latency distributions from production servers, and to identify multi-modal distributions and outliers.

The following four pages introduce and then demonstrate different uses of frequency trails:

  1. Introduction
  2. Outliers
  3. Modes
  4. Mean

The example on the right shows a frequency trail waterfall plot, where multiple frequency trails are stacked in one image. In this example, each distribution has also been centered on its mean, with a vertical line showing the mean. For more about this visualization, see the mean page.


A frequency trail is a cross between a frequency or density plot, and a rug plot. For the bulk of the data, a frequency plot line is drawn, showing detail of the distribution mode or modes. When the data is infrequent, a rug plot is used, showing individual data points on the x-axis line. This combination provides the highest resolution visualization for both modes and outliers.

This visualization is fully introduced and explained in the Intro page.


Last updated: 08-Feb-2014