This is a histogram of Morse code by JO1FYC.
[1] http://homepage2.nifty.com/jo1fyc/sound/20051010_nikki-32.mp3
Figure 1. Histogram
ggplot(mydata, aes(x=V2, fill=V1)) + geom_histogram(binwidth=50)+facet_grid(V1 ~ .)+xlim(0,3000)
One more from JO1FYC.
[2] http://homepage2.nifty.com/jo1fyc/sound/20010915amenimomakezu.mp3
Figure 2. Histgram 2
Still more from JO1FYC.
[3] http://homepage2.nifty.com/jo1fyc/sound/20010504nikki.MP3
Figure 3. Histogram 3
Yet another from JO1FYC.
[4] http://homepage2.nifty.com/jo1fyc/sound/20010504nikki02.MP3
Figure 4. Histogram 4
Still another from JO1FYC.
[5] http://homepage2.nifty.com/jo1fyc/sound/20010504nikki03.MP3
Figure 5. Histogram 5