Vertical align test for Shiny

server.R

library(shiny)

shinyServer(function(input, output) {
   
  output$distPlot <- renderPlot({
    dist <- rnorm(input$obs)
    hist(dist)  
  })
  
  output$distPlot2 <- renderPlot({
    dist <- runif(input$obs)
    hist(dist)    
  })
})

ui.R

library(shiny)

shinyUI(pageWithSidebar(
  
  headerPanel("Vertical alignment test"),
  
  sidebarPanel(
    sliderInput("obs", 
                "Number of observations:", 
                min = 1, 
                max = 1000, 
                value = 500)
  ),
  
  mainPanel(
    div(class='row',
      div(class='span6', plotOutput("distPlot")),
      div(class='span6', plotOutput("distPlot2")))
  )
))