r - 编织 PDF 时如何去除垃圾代码

Question

我正在编织 pdf，但是当它输出我的图表时，它也输出以下内容。如何阻止 R 输出此内容？

##
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
##
## filter, lag
## The following objects are masked from 'package:base':
##
## intersect, setdiff, setequal, union
## Registering fonts with R
Importing fonts may take a few minutes, depending on the number of fonts and the speed of the system.
Continue? [y/n]
## Exiting.
## Arial Black already registered with windowsFonts().
## Arial already registered with windowsFonts().
## Arial Narrow already registered with windowsFonts().

代码:

```{r, echo=FALSE}
library(dplyr)
library(kableExtra)
library(knitr)
library(extrafont)
font_import()
loadfonts(device = 'win')

x <- seq(1,9,by = 1)

kable(x,format = 'latex', booktabs = T, caption = "A KnitR Kable")
```

Answer 1

通常有一个单独的部分，您可以在其中加载所有包并包含 message = FALSE、warning = FALSE 选项。这会使输出保持沉默，并防止文件被加载包时有时会导致的大量警告所填满:

```{r, message = FALSE, warning = FALSE}
library(dplyr)
library(kableExtra)
library(knitr)
library(extrafont)
```

```{r, echo=FALSE}
font_import()
loadfonts(device = 'win')

x <- seq(1,9,by = 1)

kable(x,format = 'latex', booktabs = T, caption = "A KnitR Kable")
```

只要确保与用户相关的警告或消息没有被静音即可。