plot_front {rPref} | R Documentation |
Pareto Front Plot
Description
Connects the points of a Pareto front (also known as Pareto frontier) and hence visualizes the dominance region of a Skyline.
Usage
plot_front(df, pref, ...)
Arguments
df |
The data frame for which the Pareto front is plotted. This may be already a maximal set w.r.t. the preference |
pref |
The preference representing the Skyline goals. This must be a Pareto composition ( |
... |
Additional graphic parameters which are passed to the |
Details
plot_front
assumes that there is an existing plot, where the value of the first preference was plotted as x-coordinate
and the value of the second preference as y-coordinate.
Note that plot_front
is only recommended if you want to use the plotting functionality from base R.
If you prefer to use ggplot2, we recommend using geom_step
for plotting the Pareto front.
See vignette("visualization", package = "rPref")
for examples.
Examples
# plots Pareto fronts for the hp/mpg values of mtcars
show_front <- function(pref) {
plot(mtcars$hp, mtcars$mpg)
sky <- psel(mtcars, pref)
plot_front(mtcars, pref, col = rgb(0, 0, 1))
points(sky$hp, sky$mpg, lwd = 3)
}
# do this for all four combinations of Pareto compositions
show_front(low(hp) * low(mpg))
show_front(low(hp) * high(mpg))
show_front(high(hp) * low(mpg))
show_front(high(hp) * high(mpg))
# compare this to the front of a intersection preference
show_front(high(hp) | high(mpg))