Shiny/ggvis 对子集图数据的反应性

Question

在看到关于 GGVIS 的演讲后，我一直在尝试创建我的第一个 Shiny/ggvis 应用程序，但没有成功。我的情节在 R 中有效，但是当我尝试将其迁移到 Shiny 应用程序以在网络上显示时，我什么也得不到。显示单选按钮，据我所知，它似乎在工作（我使用 rStudio/Shiny/Reactivity 教程中的表格进行了测试，但它似乎与我的 ggvis 图不太合适）。我一直在关注 Rstudio 上的教程并使用 ggvis 源代码中演示文件夹中的片段。我正在尝试创建一个简单的内核密度图，该图根据用户输入对数据进行子集化并显示分布。附件是我迄今为止所拥有的一个可重复的例子。对于我在这里缺少的内容，我将不胜感激。

ui.R

# clear memory & load packages
      rm(list=ls())

      library(shiny)
      library(ggvis)

# Define UI for distribution application
    shinyUI(fluidPage(

# Application title
         titlePanel("Diamond Carats by Color/Cut"),

# Sidebar with controls to select subset
          sidebarLayout(
          sidebarPanel(
            radioButtons("cut", "Diamond Cut:",
                         c("Ideal" = "IDEAL",
                           "Premium" = "IDEAL",
                           "Good" = "GOOD",
                           "Very Good" = "VGOOD"))
          ),

#  Display your plot created by GGvis        
            mainPanel(ggvis_output("my_plot"))

          )
        ))

---

服务器.R

# clear memory & load packages    
        rm(list=ls())

        library(shiny)
        library(ggvis)

# Define server logic for distribution application

        shinyServer(function(input, output, session) {

# load your data      
          dataset <- diamonds

# Reactive expression to generate the subset.      
          datasetInput <- reactive({                
            selection <-switch(input$cut,
                               IDEAL = "Ideal",
                               PREM = "Premium",
                               GOOD = "Good",
                               VGOOD = "Very Good") 

            subset(dataset, cut == selection)                   
          })


# Generate your plot using GGvis and your reactive inputs      
          gv <- reactive({

            ggvis(datasetInput(), by_group(color),
                  props(x = ~carat,
                        stroke = ~color,
                        fill = ~color,
                        fillOpacity := 0.2,
                        fillOpacity.hover := 0.7)) +
              layer_density()                                
          })


# necessary additions for ggvis integration to shiny        
          output$controls <- renderControls(gv)
          observe_ggvis(gv, "my_plot", session)               
        })

编辑：为了跟进这个问题，我注意到如果我删除以下内容：

            by_group(color)

和

            stroke = ~color, 
            fill = ~color,

从我在 server.R 中创建图形的调用中，图形运行（尽管没有多色分组，这是我最初所追求的）并且单选按钮成功选择了我的数据子集。如前所述，当我只是在 R 中运行图形时，不使用反应子集功能，图形能够运行并通过菱形颜色改变描边/填充。目前 Shiny 与 ggvis 交互是否不支持此功能？还是我只是以某种方式误解了这个功能？这是我更新的代码，所以你可以看到我的结果：

ui.R

# clear memory & load packages
      rm(list=ls())

      library(shiny)
      library(ggvis)

# Define UI for distribution application
    shinyUI(fluidPage(

# Application title
         titlePanel("Diamond Carats by Color/Cut"),

# Sidebar with controls to select subset
          sidebarLayout(
          sidebarPanel(
            radioButtons("cut", "Diamond Cut:",
                         c("Ideal" = "IDEAL",
                           "Premium" = "IDEAL",
                           "Good" = "GOOD",
                           "Very Good" = "VGOOD"))
          ),

#  Display your plot created by GGvis        
            mainPanel(ggvis_output("my_plot"))

          )
        ))

---

服务器.R

# clear memory & load packages    
        rm(list=ls())

        library(shiny)
        library(ggvis)

# Define server logic for distribution application

        shinyServer(function(input, output, session) {

# load your data      
          dataset <- diamonds

# Reactive expression to generate the subset.      
          datasetInput <- reactive({                
            selection <-switch(input$cut,
                               IDEAL = "Ideal",
                               PREM = "Premium",
                               GOOD = "Good",
                               VGOOD = "Very Good") 

            subset(dataset, cut == selection)                   
          })


# Generate your plot using GGvis and your reactive inputs      
          gv <- reactive({

            ggvis(datasetInput(),
                  props(x = ~carat,
                        fillOpacity := 0.2,
                        fillOpacity.hover := 0.7)) +
              layer_density() 

          })


# necessary additions for ggvis integration to shiny        
          output$controls <- renderControls(gv)
          observe_ggvis(gv, "my_plot", session)               
        })

Answer 1

进一步搜索表明这是 ggvis 的一个已知错误：https://github.com/rstudio/ggvis/issues/71