title: How to add horizontal scroll bar for a ggplot plot in RMarkdown html
body: <p>I have recently started using RMarkdown for reporting purposes. A specific report I am working on contains tables and plots for data acquired from many experiments carried out over the years - sort of updating and summarising data quickly. </p>
  
  <p>While I have found a way to add scrollbars/scroll boxes for tables (by using Kable) and code chunk outputs, I have not been able to add scrollbars for plots. Most of plots are not big and its not an issue, but for one/two plots there are many categories and I need the plot to not resize when browser window size is changed or make the width of the entire page huge. Ideally, if possible, it should be of a specific size and in a scrollbox of fixed width.  </p>
  
  <p>Here is an example of the kind of plot I am trying to do. Any suggestions are welcome!</p>
  
  <pre><code>---
  title: "Add horizontal scrol"
  author: "KTy"
  date: "9/21/2018"
  output: html_document
  ---
  
  ```{r setup, include=FALSE}
  knitr::opts_chunk$set(echo = TRUE)
  require(ggplot2)
  ```
  
  ## R Markdown
  ### Want to add horizontal scroll bar around a plot
  
  ```{r rnorm_box_violin}
  set.seed(2300)
  xdf1 &lt;- data.frame(  var1 = rnorm(  10000 , mean = 5000 , sd = 10) , str1 = rep("a0",10000)  )
  
  for ( x in 10:50 ){
    n &lt;- sample(x = c(10,0.1) , size = 1)
    xdf2 &lt;- data.frame( var1 = rnorm(  x*n*1000 , mean = 5000+(x/2) , sd = 10) , str1 = rep(paste0("a",x),x*n*1000))
    xdf1 &lt;- rbind(xdf1,xdf2)
    }
  
  plot1 &lt;- ggplot(  data = xdf1  , aes( x = str1 , y = var1  ))  + 
    geom_violin(fill='grey90', scale = 'count', colour = 'grey70') + 
     geom_boxplot( width = 0.2 ,  alpha = 0.1 , colour = 'grey30')+
    theme_bw()+
    theme(axis.text.x =  element_text(angle = 45, hjust = 1 ,vjust = 1))
  ```
  Produces this plot:
  ```{r plot_it , echo = FALSE, width = 20 , height = 7}
  plot1
  ```
  </code></pre>
  
  <p>I am using RStudio on Mac. I hope what I am asking makes sense, please leave comments if anythings is not clear and I can try to explain further. Cheers, Thank you!</p>