inst/examples/moving.block-ex.R

In yihui/animation: A Gallery of Animations in Statistics and Utilities to Create Animations

## (1) Brownian motion
#  block length: 101 (i.e. 300-200+1)
oopt = ani.options(nmax = ifelse(interactive(), 200, 2), interval = 0.1)
#  plot y = dat against x = i + 1:block
#  customize xlab and ylab with 'i' and 'block'
#  restrict ylim using the range of 'dat'
moving.block(
  dat = cumsum(rnorm(300)),
  FUN = function(..., dat = dat, i = i, block = block) {
    plot(..., x = i + 1:block, xlab = sprintf('block length = %d', block),
         ylim = range(dat), ylab = sprintf('x[%s:%s]', i + 1, i + block))
  }, type = 'o', pch = 20)


## (2) Word counts of Hu's speech (block = 10; length(HuSpeech) = 75)
#  see any pattern in the President's speech?
ani.options(nmax = ifelse(interactive(), 66, 2), interval = 0.5)
moving.block(
  dat = HuSpeech,
  FUN = function(..., dat = dat, i = i, block = block) {
    plot(..., x = i + 1:block, xlab = 'paragraph index', ylim = range(dat),
         ylab = sprintf('HuSpeech[%s:%s]', i + 1, i + block))
  }, type = 'o', pch = 20)


## (3) sunspot data: observe the 11-year cycles
#  block = 11 years x 12 months/year = 132
#  set interval greater than 0 if your computer really rocks!
ani.options(nmax = ifelse(interactive(), 2857, 2), interval = 0)
spt.att = tsp(sunspot.month)
#  the time index (we need it to correctly draw the ticks of x-axis)
ts.idx = seq(spt.att[1], spt.att[2], 1/spt.att[3])
moving.block(
  dat = sunspot.month, block = 132,
  FUN = function(..., dat = dat, i = i, block = block) {
    plot(..., x = ts.idx[i + 1:block], xlab = sprintf('block length = %d', block),
         ylim = range(dat), ylab = sprintf('sunspot.month[%s:%s]', i + 1, i + block))
  }, type = 'o', pch = 20)


## (4) earth quake: order the data by 'depth' first
#  see how the locations change as 'depth' increases
ani.options(nmax = ifelse(interactive(), 900, 2), interval = 0.01)
#  compute the mean depth for each block of data
moving.block(
  quakes[order(quakes$depth), c('long', 'lat')],
  FUN = function(..., dat = dat, i = i, block = block) {
    plot(..., xlab = sprintf('%s[%s:%s]', colnames(dat)[1], i + 1, i + block),
         ylab = sprintf('%s[%s:%s]', colnames(dat)[2], i + 1, i + block),
         xlim = range(dat[, 1]), ylim = range(dat[, 2]),
         main = sprintf('Mean Depth = %.3f', mean(sort(quakes$depth)[i + 1:block])))
  }, pch = 20, col = rgb(0, 0, 0, 0.5))

ani.options(oopt)