In Hans Rosling's attractive talk ``Debunking third-world myths with the best
stats you've ever seen'', he used a lot of bubble plots to illustrate trends
behind the data over time. This function gives an imitation of those moving
bubbles, besides, as this function is based on symbols, we can
also make use of other symbols such as squares, rectangles, thermometers,
etc.
Rosling.bubbles(
x,
y,
data,
type = c("circles", "squares", "rectangles", "stars", "thermometers", "boxplots"),
bg,
xlim = range(x),
ylim = range(y),
main = NULL,
xlab = "x",
ylab = "y",
...,
grid = TRUE,
text = 1:ani.options("nmax"),
text.col = rgb(0, 0, 0, 0.5),
text.cex = 5
)NULL.
the x and y co-ordinates for the centres of the bubbles (symbols).
Default to be 10 uniform random numbers in [0, 1] for each single image
frame (so the length should be 10 * ani.options('nmax'))
the type and data for symbols; see symbols.
The default type is circles.
see symbols. Note that
bg has default values taking semi-transparent colors.
logical; add a grid to the plot?
a character vector to be added to the plot one by one (e.g. the year in Rosling's talk)
color and magnification of the background text
Yihui Xie
Suppose we have observations of \(n\) individuals over
ani.options('nmax') years. In this animation, the data of each year
will be shown in the bubbles (symbols) plot; as time goes on, certain trends
will be revealed (like those in Rosling's talk). Please note that the
arrangement of the data for bubbles (symbols) should be a matrix like
\(A_{ijk}\) in which \(i\) is the individual id (from 1 to n), \(j\)
denotes the \(j\)-th variable (from 1 to p) and \(k\) indicates the time
from 1 to ani.options('nmax').
And the length of x and y should be equal to the number of rows
of this matrix.
Examples at https://yihui.org/animation/example/rosling-bubbles/
TED talk: https://www.ted.com/talks/hans_rosling_the_best_stats_you_ve_ever_seen