title: Packages missing in shiny-server
body: <p>I am trying to create a web application using shiny. It requires me to load a package I have installed on my computer. For example:</p>
  
  <pre><code>## Contents ui.R:
  library(shiny)
  library(plyr)
  
  shinyUI(pageWithSidebar(
  
    headerPanel("Hello Shiny!"),
  
    sidebarPanel(
      sliderInput("obs", 
                  "Number of observations:", 
                  min = 0, 
                  max = 1000, 
                  value = 500)
    ),
  
    mainPanel(
      plotOutput("distPlot")
    )
  ))
  
  ## Contents server.R:
  library(shiny)
  library(plyr)
  
  shinyServer(function(input, output) {
  
    output$distPlot &lt;- renderPlot({
  
      # generate an rnorm distribution and plot it
      dist &lt;- rnorm(input$obs)
      hist(dist)
    })
  })
  </code></pre>
  
  <p>This works fine if I run it locally (using <code>runApp</code>) but when I try to run it via my server (same computer) I get the error that the <code>plyr</code> package (or any other package I try to use this way) is not installed. How could I use extra packages in shiny server?</p>