Experiments with shiny and ggplot2

server.r

library(shiny)
library(datasets)
library(ggplot2)

tg <- ToothGrowth
tg$dose <- factor(tg$dose)

# Define server logic
shinyServer(function(input, output) {
     
  # Return the formula text for printing as a caption
  output$caption <- reactiveText(function() {
    "A title here"
  })

  # Generate a plot of the requested variable against mpg and only 
  # include outliers if requested
  output$tgPlot <- reactivePlot(function() {

    # Figure out the aesthetic mappings. color_var requires special handling
    # because it can be "none".
    if (input$color_var == "") {
      aes_mapping <- aes_string(x = input$x_var, y = "len")
    } else {
      aes_mapping <- aes_string(x = input$x_var, y = "len",
                                fill = input$color_var)
    }

    p <- ggplot(tg, mapping = aes_mapping)



    if (input$geom_violin) {
      p <- p + geom_violin(trim = input$violin_trim,
                           adjust = input$violin_adjust,
                           position = position_dodge(input$dodgewidth))
    }


    if (input$geom_boxplot) {
      if (input$boxplot_outliers)
        outlier_color <- "black"
      else
        outlier_color <- NA

      p <- p + geom_boxplot(width = input$boxplot_width,
                            notch = input$boxplot_notch,
                            outlier.colour = outlier_color,
                            outlier.size = input$boxplot_outlier_size,
                            position = position_dodge(input$dodgewidth))
    }


    if (input$geom_dotplot) {
      p <- p + geom_dotplot(binaxis="y", stackdir=input$dotplot_stackdir,
                            method = input$dotplot_method,
                            binwidth = input$dotplot_binwidth,
                            alpha = input$dotplot_alpha,
                            # Using position=position_dodge() is broken in ggplot2 0.9.2.1.
                            # So just use "dodge"
                            position = "dodge")
    }


    if (input$geom_point) {
      p <- p + geom_point(shape = 21, size = input$point_size,
                          colour = "black",
                          alpha = input$point_alpha,
                          position = position_dodge(input$dodgewidth))
    }

    print(p)
  })
})

ui.r

library(shiny)

# Define UI for miles per gallon application
shinyUI(pageWithSidebar(
  
  # Application title
  headerPanel("Tooth Growth"),
  
  # Sidebar with controls to select the variable to plot against mpg
  # and to specify whether outliers should be included
  sidebarPanel(
    selectInput("x_var", "x variable:",
                c("Dose"            = "dose",
                  "Supplement Type" = "supp")),
    selectInput("color_var", "fill color variable:",
                c("None"            = "",
                  "Dose"            = "dose",
                  "Supplement Type" = "supp"),
                selected = "Supplement Type"),

    conditionalPanel(
      condition = "input.color_var != 'none'",
      tags$div(
        class = "well",
        sliderInput("dodgewidth", "Horizontal dodging width (for different colors):",
                    min = 0.1, max = 1, value = .9, step = 0.1)
      )
    ),


    checkboxInput("geom_point", "Geom: point", FALSE),
    conditionalPanel(
      condition = "input.geom_point == true",
      sliderInput("point_alpha", "Alpha (transparency):",
                  min = 0.0, max = 1, value = 1, step = 0.1),
      sliderInput("point_size", "Size:",
                  min = 0.5, max = 8, value = 3, step = 0.5)
    ),


    checkboxInput("geom_dotplot", "Geom: dotplot", TRUE),
    conditionalPanel(
      condition = "input.geom_dotplot == true",
      radioButtons("dotplot_method", "Binning method",
                   c("Dot-density"                 = "dotdensity",
                     "Histodot (regular spacing)" = "histodot")),
      sliderInput("dotplot_binwidth", "Bin width:",
                  min = 0.5, max = 3, value = 1, step = 0.25),
      sliderInput("dotplot_alpha", "Alpha (transparency):",
                  min = 0.0, max = 1, value = 1, step = 0.1),

      selectInput("dotplot_stackdir", "Stacking direction:",
                  c("Centered"         = "center",
                    "Centered-aligned" = "centerwhole"))
    ),


    checkboxInput("geom_boxplot", "Geom: boxplot", FALSE),
    conditionalPanel(
      condition = "input.geom_boxplot == true",
      sliderInput("boxplot_width", "Width:",
                  min = 0.1, max = 1, value = .5, step = 0.1),
      checkboxInput("boxplot_notch", "Notched", FALSE),
      checkboxInput("boxplot_outliers", "Show outliers", TRUE),

      conditionalPanel(
        condition = "input.boxplot_outliers == true",
        sliderInput("boxplot_outlier_size", "Outlier size:",
                    min = 1, max = 8, value = 3, step = 1)
      )
    ),


    checkboxInput("geom_violin", "Geom: violin", FALSE),
    conditionalPanel(
      condition = "input.geom_violin == true",
      sliderInput("violin_adjust", "Bandwidth adjustment ratio:",
                  min = 0.25, max = 2, value = 1, step = 0.25),
      checkboxInput("violin_trim", "Trim violins to data range", TRUE)
    )

  ),
  
  # Show the caption and plot of the requested variable against mpg
  mainPanel(
    h3(textOutput("caption")),
    
    plotOutput("tgPlot")
  )
))