Visualisation of Standard Distributions

Stefan
juli 20 2015

Coursera Data Science Specialization Project assignment

Purpose of the shiny app

The application attempts to visualise common standard probability distributions by comparing the histogram of random draws with the theoretical distribution.

  • Normal Distribution
  • Poisson Distribution
  • Chi Square Distribution
  • Student's t Distribution

For each distribution following items are shows :

  • histogram of random draws
  • mean of the the random draws as vertical line
  • theoretical distribution as blue curve

Example for Chi Square Distribution

The PDF (probability density function) for the chi square distribution is parametrised by the degrees of freedom. The larger the sample size of random draws, the closer the result will match the theoretical distribution.

plot of chunk unnamed-chunk-1

Example for Poisson Distribution

The Poisson distribution is the only discrete probability distribution in this app and therefore points are used to show the theoretical distribution.

plot of chunk unnamed-chunk-2

Extendibility

The server.R and ui.R source code are written in such a way that the app can be extended very easily with more distritubions.

Visit https://github.com/stefMT2970/DevDataProducts
download and simply modify the code.