mean_vs_median_normal_movie: Sample mean vs sample median: normally distributed data

In paulnorthrop/stat1004: stat1004: Introduction to Probability and Statistics at UCL

Description

A movie to compare the sampling distributions of the sample mean and sample median based on a random sample of size n from a standard normal distribution.

Usage

mean_vs_median_normal_movie(n = 10, delta_n = 1, pos = 1,
  envir = as.environment(pos))

Arguments

n	An integer scalar. The size of the samples drawn from a standard normal distribution.
delta_n	A numeric scalar. The amount by which the value of the sample size is increased/decreased after one click of the +/- button.
pos	A numeric integer. Used in calls to assign to make information available across successive frames of a movie. By default, uses the current environment.
envir	An alternative way (to pos) of specifying the environment. See environment.

Details

The movie is based on simulating repeatedly samples of size n from a standard normal N(0,1) distribution. It contains three plots. The top plot contains a histogram of the most recently simulated dataset, with the N(0,1) probability density function (p.d.f.) superimposed.

Each time a sample is simulated the sample mean and sample median are calculated. These values are indicated on the top plot as a filled circle: a red circle for the sample mean and a blue circle for the sample median; and are added to the values plotted in the middle and bottom plots.

The plot in the middle contains a histogram of the sample means of all the simulated samples. The p.d.f.s of the sampling distributions of the sample mean (thick red line) and the sample medians (thin blue line) are superimposed.

The plot on the bottom contains a histogram of the sample medians of all the simulated samples. The p.d.f.s of the sampling distributions of the sample mean (thin red line) and the sample medians (thick blue line) are superimposed.

An extra sample is produced by clicking the + button next to "number of samples of size n". [Ignore the - button.] The value of the sample size can be changed using the +/- buttons in the panel.

Value

Nothing is returned, only the animation is produced.

See Also

movies: general information about the movies.

mean_vs_median_t_movie: compares the sampling distributions of the sample mean and sample median based on a random sample of size n from a Student's t distribution.

Examples

# Load package rpanel
# [Use install.packages("rpanel") if necessary]
library(rpanel)

# Produce movie using values from the Aussie births data
## Not run: 
mean_vs_median_normal_movie()

## End(Not run)

paulnorthrop/stat1004 documentation built on Nov. 17, 2019, 3:49 a.m.