US 2000 Presidential Election Movie: straightening scatter plots

Source: R/USelection_movie.R

A movie to illustrate the effects of the transformation of variable(s) on the appearance of a scatter plot, using the 2000 U.S. Presidential Election data from Florida.

scatterplot_movie(
  x,
  y,
  delta_power = 0.1,
  pos = 1,
  envir = as.environment(pos),
  ...
)

Arguments

x, y

Numeric vectors of the same length. Pairs of values to plot using a scatter plot. The values in x will be plotted on the horizontal axis, the values in y on the vertical axis.

delta_power

A numeric scalar. The amount by which the powers of x and y increase/decrease after one click of a button in the parameter window.

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.

...

Further arguments to be passed to plot.

Value

Nothing is returned, only the animation is produced.

Details

scatterplot_movie produces a scatter plot of the input variables x and y which can then be animated by transforming x and/or y using power transformations. [In fact a Box-Cox transformation is used.] The power of x and y is chosen using a parameter windows containing buttons labelled + and -. Clicking + increases the power by delta_power and clicking - decreases the power by delta_power.

See also

stat0002movies: general information about the movies.

USelection: description of the 2000 U.S. Presidential Election data from Florida.

Examples

# Proportion of votes gained by Buchanan
pbuch <- 100 * USelection$buch / USelection$tvot

# Produce plot
scatterplot_movie(x = USelection$npop, y = pbuch)

# Change the plotting character
scatterplot_movie(x = USelection$npop, y = pbuch, pch = 16)


# Identify Palm Beach using a different plotting character
county_name <- USelection[, "co_names"]
pb <- which(county_name == "PalmBeach")
my_pch <- rep(16, length(county_name))
my_pch[pb] <- 4
scatterplot_movie(x = USelection$npop, y = pbuch, pch = my_pch)