Shiny::renderPlot - cannot set resolution reactive
<p>Hi my second week with shiny. I'm coding an app, where a plot window and some plot control buttons needs to appear at some point. I use <code>renderUI()</code> and <code>renderPlot()</code>. I can have the user to update plot parameters <code>renderPlot(expr={ [inside here] })</code>.</p>

<p>,but I cannot have the user to change the plot resolution <code>renderPlot(res=[some reactive variable outside here],expr={ })</code></p>

<p>I have posted test example below, Thanks alot.</p>

<pre><code>library(shiny)

ui = fluidPage(
  uiOutput('thisPlot'),
  uiOutput('plotOptions')
)

server &lt;- function(input, output) {
  #some plot options which will appear by some event
  output$plotOptions &lt;- renderUI({
    if(TRUE) {list(
      radioButtons('plot.log', 'log axis',
                   c('none'= '' ,
                     'x'   = 'x',
                     'y'   = 'y',
                     'xy'  = 'xy'),sel=NULL),
    sliderInput('plotRes', "resolution",min=50,max=200,value=75)

    )}
  })


#render plot // plotRes does not respond
output$thisGraphicsDev &lt;- renderPlot(res=input$plotRes,expr={
 plot(x=runif(1000),y=runif(1000),log=input$plot.log)
})

#write plot to ui
output$thisPlot &lt;- renderUI({plotOutput('thisGraphicsDev')})

}
shinyApp(ui, server)
</code></pre>