为什么我的 R Shiny 应用程序无法正常显示？

Question

我显然在这里遗漏了一些东西，但我对 Shiny 应用程序还很陌生（我之前只做过几个），而且我仍在学习它们的原理。

此应用（将自行运行）适用于输入端（滑块和文本输入），但输出（应该是表格）不会显示。

代码如下：

# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#

library(shiny)

ui <- fluidPage(

    # Application title
    titlePanel("CHD Risk Calculator"),

    sidebarLayout(
        sidebarPanel(
            sliderInput("BMI",
                        "Your BMI (kg/m^2 OR (703*lbs)/in^2):",
                        min = 10,
                        max = 70,
                        value = 24),
            textInput("Age",
                      "Your Age:")
        ),

        mainPanel(
           tableOutput("")
        )
    )
)

server <- function(input, output) {

    inputdata <- reactive({
        data <- data.frame(
            MyBMI = as.integer(input$BMI),
            MyAge = as.integer(input$age))
        data
    })
    
    output$result <- renderTable({
        data = inputdata()
        chdrisk = -6.293 + (0.0292*data$BMI) + (0.07409*data$age)
        resultTable = data.frame(
            Result = "Your risk of Coronary Heart Disease (CHD) is",
            Risk = chdrisk)
        resultTable
        
    })
}

# Run the application 
shinyApp(ui = ui, server = server)

我在这里错过了什么？

谢谢！

Answer 1

这里发生了一些事情

1. 您的tableOutput() 已分配给outputID=""；将此更改为"result"
2. 滑块和文本的输入称为 BMI 和年龄，但在反应式中，您将它们称为 BMI 和年龄
3. reactive 中的数据框有两列，MyBMI 和 MyAge，但后来你这样引用它们：data$BMI 和 data$age

这是一个修正版

# This is a Shiny web application. You can run the application by clicking
# the 'Run App' button above.
#
# Find out more about building applications with Shiny here:
#
#    http://shiny.rstudio.com/
#

library(shiny)

ui <- fluidPage(
  
  # Application title
  titlePanel("CHD Risk Calculator"),
  
  sidebarLayout(
    sidebarPanel(
      sliderInput("BMI",
                  "Your BMI (kg/m^2 OR (703*lbs)/in^2):",
                  min = 10,
                  max = 70,
                  value = 24),
      textInput("Age",
                "Your Age:")
    ),
    
    mainPanel(
      tableOutput("result")
    )
  )
)

server <- function(input, output) {
  
  inputdata <- reactive({
    data <- data.frame(
      MyBMI = as.integer(input$BMI),
      MyAge = as.integer(input$Age))
    data
  })
  
  output$result <- renderTable({
    data = inputdata()
    chdrisk = -6.293 + (0.0292*data$MyBMI) + (0.07409*data$MyAge)
    resultTable = data.frame(
      Result = "Your risk of Coronary Heart Disease (CHD) is",
      Risk = chdrisk)
    resultTable
    
  })
}

# Run the application 
shinyApp(ui = ui, server = server)