我想使用免费字体Lato in ggplot2因为我的 R markdown 文档的其余部分就是用这种字体设置的。
该字体已安装在我的系统上，并且可以在字体簿中找到（只有一次).
所有可用字体均加载extrafont封装并注册在extrafontdb.
当我将 Markdown 文档编织为 PDF 时，所有文本均正确排版Lato。但是，我的 ggPlots 的绘图标签未显示。
我还收到以下警告消息：
Warning in grid.Call(C_textBounds, as.graphicsAnnot(x$label), x$x, x$y, : font width unknown for character 0x20
嵌入文档中包含的字体后extrafont::embed_fonts所有图形的绘图标签均使用Lato作为字体，但是
下面提供了一个 MWE，包括带有和不带有 Lato 字体的 ggPlot 图形（Lato 可在此处免费获取）
要随后嵌入字体，需要运行embed_fonts("TestRmd.pdf", outfile="TestRmd_embedded.pdf")
任何帮助是极大的赞赏！
---
title: "Embedding Fonts in PDF"
output: pdf_document
urlcolor: blue
---
```{r echo=FALSE}
library(ggplot2)
```
### Plot with standard font {#standard}
```{r echo=FALSE, out.width = '30%'}
ggplot(mtcars, aes(x=wt, y=mpg)) + geom_point() +
ggtitle("Fuel Efficiency of 32 Cars") +
xlab("Weight (x1000 lb)") + ylab("Miles per Gallon")
```
### Load fonts and set font for ggplots globally
```{r include=FALSE}
# install.packages("extrafont") # see https://github.com/wch/extrafont/
library(extrafont)
# font_import() # run once
loadfonts() # loadfonts
# globally set ggplot2 theme and font ("Lato Light")
theme_set(theme_minimal(base_size=12, base_family="Lato Light"))
```
### Plot with newly set standard font (= Lato) {#lato}
```{r echo=FALSE, out.width = '30%'}
ggplot(mtcars, aes(x=wt, y=mpg)) + geom_point() +
ggtitle("Fuel Efficiency of 32 Cars") +
xlab("Weight (x1000 lb)") + ylab("Miles per Gallon")
```
### Plot with Impact font {#impact}
```{r echo=FALSE, out.width = '30%'}
ggplot(mtcars, aes(x=wt, y=mpg)) + geom_point() +
ggtitle("Fuel Efficiency of 32 Cars") +
xlab("Weight (x1000 lb)") + ylab("Miles per Gallon") +
theme(text=element_text(size=16, family="Impact"))
```
### Run to embed fonts
```{r eval=FALSE, include=TRUE}
embed_fonts("TestRmd.pdf", outfile="TestRmd_embedded.pdf")
```
### Links test
Links test 1 (internal reference): [Headline standard](#standard)
Links test 2 (URL): [RStudio has become a Public Benefit Corporation](https://blog.rstudio.com/2020/01/29/rstudio-pbc)
一个更简单的问题，但可能与同一问题相关：
library(extrafont)
extrafont::font_import()
p <- ggplot(iris, aes(Sepal.Length, Sepal.Width)) + geom_point() + theme_minimal(base_size=10, base_family="Lato Light")
ggsave(p, filename = "iris.pdf")
保存的 pdf 中的绘图不包含任何标签。使用cairo_pdf正如对几个 SO 的建议（例如1, 2）网站没有帮助并导致以下错误：
ggsave(p, filename = "iris.pdf", device = cairo_pdf)
# In dev(filename = filename, width = dim[1], height = dim[2], ...) :
# failed to load cairo DLL
我试图让它工作使用extrafont但没有成功。我仍然不太确定，但我认为这是一个错误。这是使用该包的解决方案showtext:
---
title: "Embedding Fonts in PDF"
output: pdf_document
urlcolor: blue
---
```{r include=FALSE}
# notice the chunk option 'fig.showtext' that tells R to use the showtext
# functionalities for each ne graphics device opened
knitr::opts_chunk$set(dev = 'pdf', cache = FALSE, fig.showtext = TRUE)
library(ggplot2)
library(showtext)
font_add(family = "Lato", regular = "/Users/martin/Library/Fonts/Lato-Light.ttf")
```
### Plot with newly set standard font (= Lato) {#lato}
```{r echo=FALSE, out.width = '100%'}
ggplot(mtcars, aes(x=wt, y=mpg)) +
geom_point() +
ggtitle("Fuel Efficiency of 32 Cars") +
xlab("Weight (x1000 lb)") +
ylab("Miles per Gallon") +
theme(text = element_text(family="Lato"))
```
