R 如何将旋转的 x 标签组放在带标签的括号中

它不一定很漂亮，因为它大多是硬编码的，但它可能会给出一个大致的 idea ，并成为一个开始.其 idea 是在文本上涂上gsub个，从而在segments上涂上白色的ASCII框.

cls <- c('#8E83C0', '#7F004B')

png('foo.png', 600, 500)

par(mar=c(17, 5, 4, 6))

## barplot
b <- barplot(M, beside=TRUE, col=cls, log='y', ylim=c(0.1, 100), yaxt='n', border=cls, ylab='Percent of genes')
cb <- colMeans(b)
axis(side=1, at=cb, labels=FALSE, srt=45, tck=0)
axis(side=2, at=c(.1, 1, 10, 100), las=2)
axis(side=4, at=c(.1, 1, 10, 100), labels=c(.1, 1, 10, 100)*200, las=2)
mtext(side=4, line=3, 'Number of genes')
box()
legend('topleft', pch=15, col=cls, legend=c('Rice', 'Arabidopsis'), bty='n')

## selections
s <- matrix(c(1, 3, 4, 15, 16, 18), 2)

segments(cb[s], .08, cb[s] - 6, .0002, cex=10, xpd=TRUE)  ## draw diagonal lines
text(x=colMeans(b), y=0.08, labels=gsub('.', '\u{2588}', labs), col='white',  ## delete text background
     xpd=TRUE, srt=75, adj=1, cex=.45, font=2)
text(x=colMeans(b), y=0.08, labels=labs, xpd=TRUE, srt=75, adj=1, cex=.8)  ## add text
segments(cb[s[seq_along(s) %% 2 == 1]] - 6, .0002, cb[s[seq_along(s) %% 2 == 0]] - 6,  ## horiz. lines
         xpd=TRUE)

text(x=cb[colMeans(s)] - 4, .00015,  ## add labels
     labels=c('Cellular location', 'Molecular function', 'Biological process'), xpd=TRUE)

dev.off()

Data:个

M <- structure(c(2.80726227650382, 2.64256293274864, 7.0102982246191, 
7.5018148086326, 25.6501702479728, 25.0712633160012, 4.68983170461288, 
4.70906566370853, 0.884917181175275, 0.937570946155162, 20.7375441378035, 
20.1152922600914, 56.670251722557, 56.2605524666463, 3.94515839835875, 
4.01074867385038, 9.16121956424095, 8.91395744490961, 26.8659730117826, 
27.8972725231774, 14.8268139881184, 15.3903380377903, 0.25900960776686, 
0.258869902594842, 29.8213455626689, 29.4996857430132, 13.5915802573365, 
14.3385613824498, 36.6442873514434, 35.5400788324485, 0.233886747548567, 
0.22457963117021, 11.5138271223363, 12.3439712437831, 10.4035068344801, 
10.2619581657598), dim = c(2L, 18L))

labs <- c('biological regulation', 'cellular process', 'detoxification', 'developmental process',
          'growth', 'homeostatic process', 'immune system process', 'localization', 'locomotion',
          'metabolic process', 'multicellular organismal process', 'negative regulation of biological process',
          'pigmentation', 'positive regulation of biological process', 'regulation of biological process',
          'reproduction', 'reproductive process', 'response to stimulus')