闪亮:动态输出元素/图的数量

Question

我想进行反应显示,根据输入选择器的哪个值选择显示不同数量的绘图.在mtcars数据集的情况下,假设我想让用户选择在Nr之间切割.Gears或Nr.Carcarratos为要生产的地块.

看着 unique(mtcars$gear)我们看到它有4 3 53个可能的值,同时unique(mtcars$carb)有4 1 2 3 6 86个可能的值.因此,我想在Nr. of Carburators选择时生成6个单独的图,并且在选择时仅绘制3个图Nr. of Gears.我曾经玩过,conditionalPanel但是我在选择器之间切换一次或两次之后总是会爆炸.救命？

闪亮的用户界面:

library(shiny)
library(googleVis)

shinyUI(bootstrapPage(
    selectInput(inputId = "choosevar",
              label = "Choose Cut Variable:",
              choices = c("Nr. of Gears"="gear",
                          "Nr. of Carburators"="carb")),
    htmlOutput('mydisplay')  ##Obviously I'll want more than one of these... 
#   conditionalPanel(...)
  ))

闪亮的服务器:

shinyServer(function(input, output) {
   #Toy output example for one out of 3 unique gear values:
    output$mydisplay <- renderGvis({
    gvisColumnChart(    
    mtcars[mtcars$gear==4,], xvar='hp', yvar='mpg' 
    )
  })  
})

Answer 1

灵感来自于此,您可以:

ui.R

shinyUI(pageWithSidebar(            
        headerPanel("Dynamic number of plots"),            
        sidebarPanel(
                selectInput(inputId = "choosevar",
                            label = "Choose Cut Variable:",
                            choices = c("Nr. of Gears"="gear", "Nr. of Carburators"="carb"))
        ),            
        mainPanel(
                # This is the dynamic UI for the plots
                uiOutput("plots")
        )
))

server.R

library(googleVis)
shinyServer(function(input, output) {
        #dynamically create the right number of htmlOutput
        output$plots <- renderUI({
                plot_output_list <- lapply(unique(mtcars[,input$choosevar]), function(i) {
                        plotname <- paste0("plot", i)
                        htmlOutput(plotname)
                })

                tagList(plot_output_list)
        }) 

        # Call renderPlot for each one. Plots are only actually generated when they
        # are visible on the web page. 


        for (i in 1:max(unique(mtcars[,"gear"]),unique(mtcars[,"carb"]))) {
                local({
                        my_i <- i
                        plotname <- paste0("plot", my_i)

                        output[[plotname]] <- renderGvis({
                                data <- mtcars[mtcars[,input$choosevar]==my_i,]
                                if(dim(data)[1]>0){
                                gvisColumnChart(    
                                        data, xvar='hp', yvar='mpg' 
                                )}
                                else NULL
                        })  
                })
        }

})

它基本上会htmlOutput动态创建绘图,并googleVis在子集中有数据时绑定绘图.