在 R 的 expression() 命令中使用 Unicode

本文介绍了在 R 的 expression() 命令中使用 Unicode的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我在 R 图中使用 expression() 以获得斜体文本.但看起来好像我不能在 ASCII 字符之外的 expression 内使用 Unicode 符号.有什么办法可以解决这个问题吗?我的目标是在我的 R 条形图中获得各种标签中的 fi 连字(以及斜体文本).

I'm using expression() in R plots in order to get italicized text. But it appears as if I cannot use Unicode symbols inside expression outside of ASCII characters. Is there some way I can work around this? My goal is to get the fi ligature in various labels in my R barplots (together with italicized text).

我在 Windows 3.0.2 版中使用 R.

I'm using R for Windows version 3.0.2.

CairoPDF(file = "Ligature1.pdf")
plot.new()
text(x =.5, y = .5, labels = "ﬁ", family = "Times New Roman")
dev.off()

CairoPDF(file = "Ligature2.pdf")
plot.new()
text(x =.5, y = .5, labels = expression(paste(italic(m), "u", "ﬁ", italic(m), sep = "")), family = "Times New Roman")
dev.off()

推荐答案

您要求解决方案.这就是全部.斜体部分需要表达式，但是fi"部分不需要，所以分开打印.

You asked for a work-around. That is all this is. The italic part needs expression, but the "ﬁ" part does not, so print them separately.

plot.new()
offset1 = strwidth(expression(paste(italic(m), "u")), units="figure")
text(x =.5, y = .5, labels = expression(paste(italic(m), "u", sep="")))
text(x =.5+offset1, y = .5, labels ="ﬁ")
offset2 = strwidth("ﬁ ")
text(x =.5+offset1+offset2, y = .5, labels = expression(italic(m)))

但是请注意，fi"的间距有些不太正确，因此当我在屏幕上计算宽度时，我欺骗并计算了fi"的宽度(额外留了一个空格).没有额外的间距，第二个 italic(m) 与fi"重叠.

But notice that something is not quite right about the spacing of the "ﬁ", so when I computed the width on the screen, I cheated and computed the width of "ﬁ " (with an extra blank). Without the extra spacing, the second italic(m) overlapped the "ﬁ".

不漂亮，但它在 Windows 下产生了想要的结果.

Not pretty, but it produces the desired result under Windows.

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