Question

好的，我有你可以在下面运行的代码。我正在尝试修改此代码：

https://gist.github.com/wch/5436415/

以便使用UI的输入动态设置max_plots。 UI的输入也是动态的。

这是我的UI.R：

shinyUI(pageWithSidebar(
  headerPanel("Dynamic number of plots"),
  sidebarPanel(
    selectInput("Desk", "Desk:" ,  c("A","B")),
   uiOutput("choose_Product"),
uiOutput("choose_File1"),
uiOutput("choose_Term1"),
sliderInput("n", "Number of plots", value=1, min=1, max=5)
  ),

  mainPanel(
    # This is the dynamic UI for the plots
    h3("Heading 1"),
    uiOutput("plots"),
   h3("Heading 2")
  )
))

这是我的Server.R：

shinyServer(function(input, output) {

  output$choose_Product <- renderUI({
    selectInput("Product", "Product:", as.list( c("Product1","Product2","Product3")))
  })

  output$choose_File1 <- renderUI({
selectInput("File1", "File1:", as.list(c("File1","File2","File3")))
  })

# Insert the right number of plot output objects into the web page

  output$plots <- renderUI({
      plot_output_list <- lapply(1:input$n, function(i) {
        plotname <- paste("plot", i, sep="")
        plotOutput(plotname, height = 280, width = 250)
      })

      # Convert the list to a tagList - this is necessary for the list of items
      # to display properly.
      do.call(tagList, plot_output_list)
  })##End outputplots

  PrintPlots<- reactive({
## I need max_plots to be set as the length of the Vector returns from getAugmentedTerms()
max_plots<-length(getAugmentedTerms(input$Desk, input$Product, input$File1))

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

for (i in 1:max_plots) {
  # Need local so that each item gets its own number. Without it, the value
  # of i in the renderPlot() will be the same across all instances, because
  # of when the expression is evaluated.
  local({
        my_i <- i
        plotname <- paste("plot", my_i, sep="")

        output[[plotname]] <- renderPlot({
           plot(1:my_i, 1:my_i,
           xlim = c(1, max_plots),
               ylim = c(1, max_plots),
               main = paste("1:", my_i, ". n is ", input$n, sep = "") )
        })
      })
    }##### End FoR Loop
  })# END OF PRINT PLOTS
})# END OF ENERYTHING

这是我的全球.R：

getAugmentedTerms<-function(desk, product, file)
{
   # this function takes 3 inputs from the UI and returns a vector
   # for simplicity I am just returning a 2 element vector
   d<-c(1,2)
   return d
}

以下是运行它的代码：

library(shiny)
runApp("C:/Users/user/Desktop/R Projects/TestDynamicPlot")

当你运行它时，你可以看到空间被创建，就像有输出图但输出是空白的。有任何想法吗？谢谢！

Answer 1

所以max_plots是硬编码的。当您启动应用程序时，循环for (i in 1:max_plots ) {（它只运行一次）会创建5（= max_plots）个新output元素（output$plot1 output$plot2 ...) which render a plot, but the plots are displayed only when the respective plotOutputs exists in the UI. The plotOutput s are created dynamically in the function lapply（1：输入$ n，函数（i）{input$n is the value of the slider. 5 plots are created but we only create输入$ n plot outputs. That's why this is dynamic even if max_plots`是硬编码的。

如果需要，可以用动态参数替换max_plots，但需要将循环包含在观察者中。每次input$n更改时都会运行。

例如：

observe({
    for (i in 1:input$n) {
        # Need local so that each item gets its own number. Without it, the value
        # of i in the renderPlot() will be the same across all instances, because
        # of when the expression is evaluated.
        local({
          my_i <- i
          plotname <- paste("plot", my_i, sep="")

          output[[plotname]] <- renderPlot({
            plot(1:my_i, 1:my_i,
                 xlim = c(1, max_plots),
                 ylim = c(1, max_plots),
                 main = paste("1:", my_i, ". n is ", input$n, sep = "")
            )
          })
        })
     }
})

我不知道你的函数返回了什么，但我想如果你将它包含在服务器函数中并且在一个反应函数中你可以读取input对象，它也可以工作。

observe({ 
    max_plots<-length(getTerm1UI(input$Desk, input$Product, input$File1))
    for(i in 1:max_plots) {
       ...

R Shiny循环显示多个图

1 个答案: