knitr rmarkdown presentation opts_chunk $ set error

Question

我正在rmarkdown中撰写演示文稿并使用＆＃39; Knit PDF＆＃39;编译为pdf。 （投影仪）。代码如下

   ---
   title: "Title"
   author: "Author"
   date: 'Date'
   output:
   beamer_presentation:
   template: default.beamer
   ioslides_presentation: default
   themeoptions: compress
   widescreen: yes
   ---

   ```{r setup, include=FALSE}
   opts_chunk$set(cache=TRUE)
   ```    

  ## Slide 1
  A

  ## Slide 2
  B

但是我收到以下错误

  Error in eval(expr, envir, enclos): object 'opts_chunk not found Calls: Anno
  <nymous> .... Execution halted

我已经使用＆＃39;设置了编织Rnw文件。领域＆＃39; knitr＆＃39;。关于如何修复此错误的任何想法？

Answer 1

将library(knitr)添加到代码块opts_chunk修复它

{r setup, include=FALSE} library(knitr) opts_chunk$set(cache=TRUE)