Using Probability Playground

Map Page

  • Select a distribution to load the page for the distribution.
  • Select the link between two distributions to load the details of their relationship.

Distribution Pages

  • Use the dropdown menu to see all available distributions.
  • Select the related distribution to see all distributions that are related to the current one.
  • Select an example to load the example.
  • Edit the distribution parameters by dragging or using the up/down keys on the vertical sliders to the right of the graph.
  • Change the mean by dragging left/right directly on the graph or using the left/right arrow keys.
  • Zoom directly on the graph or use the up/down keys to change the variance.
  • The space below each graph displays a box centered on the mean with one standard deviation either side (if the mean and variance are defined).
  • For continuous distributions, vertical lines are displayed on the graph to show the first quartile, median, and third quartile.

Display Options

  • Use the buttons above the graph to switch between displaying the probability mass/density function (pmf/pdf), the cumulative distribution function (cdf), a visualization of the process which generates the distribution, and a simulation of the generating process.
  • Use the buttons below the graphs to switch between fixing the axis ranges at their current values and having them chosen automatically.

Related Distributions

  • When a related distribution is loaded, the parameters for the related distribution are derived from the current distribution and the link between them.
  • Limiting distributions are shown with the same mean (and variance if appropriate) as the distribution they approximate.
  • The number of random variables in a sum/product/maximum/minimum can be changed using the slider next to the graph.
  • For a sampling distribution, the size of the sample can be changed using the slider next to the graph.

Glossary

cdf
Cumulative distribution function
iid
Independent and identically distributed
mgf
Moment generating function
pdf
Probability density function
pmf
Probability mass function
rv
Random variable