R闪亮：checkboxGroupInput值

Question

我是 R 新手，我在 Ui.R 中有这段代码：

library(shiny)

ui <- shinyUI(fluidPage(

  titlePanel("Test 1"),

  sidebarLayout(
    sidebarPanel(
      checkboxGroupInput("sex", "sex", c("Men", "Women")),
      textOutput("number")
   ),

   mainPanel(

   )
  )
))

Server.R 中的这段代码：

server <- shinyServer(function(session, input, output) {

  observeEvent(input$sex, {
    if (input$sex == "Men"){s<-1}
    number<-as.numeric(s)

    if (input$sex == "Women"){s<-2}
    number<-as.numeric(s)

    if (input$sex == "Men" & input$sex == "Women"){s<-5}
    number<-as.numeric(s)

    if (is.null(input$sex)) {s<-10}
    number<-as.numeric(s)

    output$number<-renderText({number})
  })
  })

所以，我不明白为什么当我选中两个复选框时“数字”不取值 5，以及如果我取消选中两个复选框，为什么“数字”不取值 10？

如果你能帮助我理解，请。

非常感谢。

编辑：如何取消选择 checkboxGrouInput “动态”？

library(shiny)

ui <- shinyUI(fluidPage(

  titlePanel("Test 1"),

  sidebarLayout(
    sidebarPanel(
      checkboxGroupInput(inputId = "sex", label = "sex",choices =  
                                    c("Men", "Women", "Children")),
      textOutput("number")
      ),

      mainPanel(
        checkboxGroupInput(inputId = "dynamic", label = "", choices = 
                                  list("Answer 1"="01", "Answer 2"="02", 
                                       "Answer 3"="03", "Answer 4"="04",
                                       "Answer 5"="05", "Answer 6"="06", 
                                       "Answer 7"="07", "Answer 8"="08", 
                                       "Answer 9"="09", "Answer 10"="10",
                                    "Answer 11"="11", "Answer 12"="12"))
       )
    )
  ))

和 Server.R ：

server <- shinyServer(function(session, input, output) { 

  output$number<-renderText({ 

    if (is.null(input$sex) ){return(10)
      updateCheckboxGroupInput(session,"dynamic",selected=character(0))}

    men      <- "Men"       %in% input$sex
    women    <- "Women"     %in% input$sex
    children <- "Children"  %in% input$sex

    if (men & women & children){
      s <- 8
      updateCheckboxGroupInput(session,"dynamic",
                             selected=list("01","02","03","04","05","06",
                                "07","08","09","10","11","12"))

      } else if (men & women){
        s <- 5
        updateCheckboxGroupInput(session,"dynamic",
                  selected=list("01","02","03","04","05","06","07","08"))

      } else if (men){
         s <-1
         updateCheckboxGroupInput(session,"dynamic",
                                    selected=list("01","02","03","04"))

      } else if (women){
         s <-2
         updateCheckboxGroupInput(session,"dynamic",
                                    selected=list("05","06","07","08"))

       } else if (children) {
          s <- 3
          updateCheckboxGroupInput(session,"dynamic",
                                    selected=list("09","10","11","12"))
       }  

       return(as.numeric(s)) 
   })
 })

非常感谢。

Answer 1

在您的代码中需要考虑的几点：

1) 如果同时选择了男性和女性，则 input$sex 的长度=2 (chr [1:2] "Men" "Women")。这条线行不通。

(input$sex == "Men" & input$sex == "Women")

2) 在应用程序初始化时 input$sex 为 NULL，并且您不能像在 if 语句中那样使用 null

if (input$sex == "Men") 

3) 你不需要observeEvent。 renderText 对 input$sex 有反应。

我对你的代码做了一些修改

library(shiny)

ui <- shinyUI(fluidPage(

  titlePanel("Test 1"),

  sidebarLayout(
    sidebarPanel(
      checkboxGroupInput(inputId = "sex", label = "sex",choices =  c("Men", "Women")),
      textOutput("number")
    ),

    mainPanel()
  )
))

server <- shinyServer(function(session, input, output) { 

  output$number<-renderText({ 

    if (is.null(input$sex) ){return(10)}

    if (length(input$sex) ==1){
        if (input$sex == "Men"){
          s<-1
        } else if (input$sex == "Women"){
          s<-2
        }
    } else{
        return(5)
    } 

    return(as.numeric(s))
  })
})

shiny::shinyApp(ui, server)

更新 - 如果您有更多选择

library(shiny)

ui <- shinyUI(fluidPage(

  titlePanel("Test 1"),

  sidebarLayout(
    sidebarPanel(
      checkboxGroupInput(inputId = "sex", label = "sex",choices =  c("Men", "Women", "Children")),
      textOutput("number")
    ),

    mainPanel()
  )
))

server <- shinyServer(function(session, input, output) { 

  output$number<-renderText({ 

    if (is.null(input$sex) ){return(10)}

    men      <- "Men"       %in% input$sex
    women    <- "Women"     %in% input$sex
    children <- "Children"  %in% input$sex

    if (men & women & children){
      s <- 8 
    } else if (men & women){
      s <- 5
    } else if (men){
      s <-1
    } else if (women){
      s <-2
    } else if (children) {
      s <- 3
    }  

    return(as.numeric(s)) 
  })
})

shiny::shinyApp(ui, server)