title: Change height parameter of rickshaw rChart within Shiny tabPanel to avoid scrollbar
body: <p>I am building a small Shiny application in which my <code>mainPanel</code> contains a <code>tabsetPanel</code>, and one of the tabs is a rickshaw rChart. If I don't have tabs and only display the rChart, everything is fine, but when the rChart is contained in a tab the tab is always shorter than the chart, imposing a scrollbar.</p>
  
  <p>I've abbreviated the below code with elipses to focus on the important parts: </p>
  
  <p>ui.R:</p>
  
  <pre><code>shinyUI(pageWithSidebar(
  
    headerPanel("..."),
  
    sidebarPanel(...),
  
    mainPanel(
      tabsetPanel(
        tabPanel("Plot",
          div(id = "myplot",
              includeCSS("rickshaw.css"),
              showOutput("plot", "rickshaw"))
        ),
        tabPanel("Raw Data", tableOutput("table"))
      )
    )
  ))  # end shinyUI
  </code></pre>
  
  <p>server.R:</p>
  
  <pre><code># some preprocessing up here
  
  shinyServer(function(input, output) {
  
    # generate checkbox options from preprocessed data
    output$modelSelection &lt;- renderUI({...})
  
    # make the rickshaw rChart
    output$plot &lt;- renderChart2({
  
      chart &lt;- Rickshaw$new()
      chart$layer(value ~ datetime, group = "variable", data = select.frame, type="area")
      chart$set(width = 600,
                height = 400,
                slider = TRUE)
      return(chart)
    })
  
    # make the raw output
    output$table &lt;- renderTable({...})    
  })
  </code></pre>
  
  <p>where <code>rickshaw.css</code> and <code>renderChart2</code> come from <a href="https://github.com/ramnathv/rCharts/issues/146" rel="nofollow noreferrer">this github bug</a> to enable interactivity.</p>
  
  <p>So the problem is that while the height in <code>chart$set</code> DOES work, the actual tab is always slightly shorter, forcing a scroll bar (still true when <code>slider=FALSE</code>). </p>
  
  <p>I had a similar problem with tabbed ggplot's in the past, which was fixed by passing a height argument to <code>plotOutput</code> which is not an option with <code>showOutput</code>.</p>
  
  <p>I have found <a href="https://stackoverflow.com/questions/17610322/change-height-attributes-of-graph-produced-with-rcharts-for-use-with-rshiny">these</a> <a href="https://github.com/ramnathv/rCharts/issues/254" rel="nofollow noreferrer">fixes</a> which apparently work for morris.js, but I've been unable to adapt them properly. </p>
  
  <p>Has anyone else has better success with rickshaw and tabbed panels?
  I'm using <code>rCharts_0.4.2</code> and <code>shiny_0.8.0</code> on <code>R version 3.0.2 (2013-09-25)</code></p>