现代统计图形 - 科学网—博客

56 第四章 元素
1 > data(Export.USCN)
2 > par(mar = c(4, 4.5, 0.1, 4.5))
3 > # 看似条形图,实为粗线条,宽度lwd = 10
4 > plot(1:13, Export.USCN$Export, xlab = "Year / Country",
5 + ylab = "US Dollars (\\$$10^{16}$)", axes = FALSE,
6 + type = "h", lwd = 10, col = c(rep(2, 6), NA,
7 + rep(4, 6)), lend = 1, panel.first = grid())
8 > # 设置x轴的刻度标记:\n的意思是换行符
9 > xlabel = paste(Export.USCN$Year, "\n", Export.USCN$Country)
10 > xlabel[7] = ""
11 > # 添加一条分隔线
12 > abline(v = 7, lty = 2)
13 > # 使用带有换行符的刻度标记
14 > axis(1, 1:13, labels = xlabel, tick = FALSE, cex.axis = 0.75)
15 > axis(2)
16 > # 换算为人民币再计算另一个坐标轴刻度(汇率8.27)
17 > ylabel = pretty(Export.USCN$Export * 8.27)
18 > axis(4, at = ylabel/8.27, labels = ylabel)
19 > mtext("Chinese RMB", side = 4, line = 2)
20 > box()
US Dollars ($10 16 )
20 30 40 50 60 70 80
1999
CN
2001
CN
2003
CN
1999
US
Year / Country
2001
US
2003
US
200 300 400 500 600
Chinese RMB
图 4.9: 双坐标轴图示:中美两国1999~2004年出口额,分别以美元和人民币
表示。注意图中x轴标签文本是如何换行的。