title: How to set dataLabel Format and axis label angle in R highcharter package
body: <p>I am experimenting with R highcharter package to create a bar chart function. the code is as below. I request help in 
  1-How to change the format of the dataLabels to percentage ? 
  2-How to set X-axis label display angle. I want to set it to 45 degrees</p>
  
  <pre><code>hcbar_categorycount_vertical &lt;- function(data=x,var=y){
  df &lt;- data.frame(prop.table(table(data[var])))
  names(df) &lt;- c(var,'Proportion')
  df$Proportion &lt;- round(df$Proportion*100,2)
  df &lt;- df%&gt;% arrange(-Proportion)
  df[,1] &lt;- as.character(df[,1])
  df[,1] &lt;- factor(df[,1], levels = df[,1])
  df$Cumulative &lt;- round(cumsum(df$Proportion),2)
  
  highchart(debug = TRUE) %&gt;%
  hc_xAxis(categories=df[[1]]) %&gt;%
  hc_yAxis(labels = list(format = "{value}%"), max = 100) %&gt;%
  hc_add_series(name=var,data=df$Proportion,type = "column",dataLabels =       list(enabled = TRUE, format='{point.label}%'))
  }
  </code></pre>
  
  <p>I am not sure what should be the syntax of "format" within dataLabel property list.The above code does not seem to work. I already referred to the highcharter vignette and this site : <a href="http://jkunst.com/highcharter/highcharts-api.html#hc_xaxis-and-hc_yaxis" rel="nofollow">http://jkunst.com/highcharter/highcharts-api.html#hc_xaxis-and-hc_yaxis</a></p>
  
  <p>But could not find an answer. Thanks for the help in advance.</p>