r - 无法弄清楚如何使用输入文本框在 Shiny 中创建和运行用户定义的 R 函数

Question

我有一个 R 脚本，需要在 R 的 shiny 包中开发和集成用户界面。

我的以下是 R 代码的一部分，我试图围绕它构建界面:

# A random normal function to generate numbers with exact mean and SD
rnorm2 <- function(n,mean,sd) { mean+sd*scale(rnorm(n)) }
age <- rnorm2(n = 10000, mean = 55 , sd = 15)
cholestrol <- rnorm2(n = 10000, mean = 200 , sd = 30)
bp <- rnorm2(n = 10000, mean = 90 , sd = 25)
df <- cbind(age, cholestrol,bp)
Org_Data <- as.data.frame(df)

由于有 9 个输入(age、cholestrol 和 bp 各 3 个)，我创建了 9 个输入框，用户在其中输入输入，然后单击按钮“我想运行我创建的 rnorm2 函数”。

我的 Shiny 应用程序代码如下:

ui.R:

library(shiny)
shinyUI(pageWithSidebar(
  headerPanel("function1"),

    sidebarPanel( 
      #Age input
      textInput(inputId = "n1", 
                label = h4("Enter n for Age:"), 
                value = ""),

      textInput(inputId = "mean1", 
                label = h4("Enter mean for Age:"), 
                value = ""),

      textInput(inputId = "sd1", 
                label = h4("Enter sd for Age:"), 
                value = ""),

      #Cholestrol input
      textInput(inputId = "n1", 
                label = h4("Enter n for Cholestrol:"), 
                value = ""),

      textInput(inputId = "mean1", 
                label = h4("Enter mean for Cholestrol:"), 
                value = ""),

      textInput(inputId = "sd1", 
                label = h4("Enter sd for Cholestrol:"), 
                value = ""),


      #Blood Pressure input
      textInput(inputId = "n1", 
                label = h4("Enter n for Blood Pressure:"), 
                value = ""),

      textInput(inputId = "mean1", 
                label = h4("Enter mean for Blood Pressure:"), 
                value = ""),

      textInput(inputId = "sd1", 
                label = h4("Enter sd for Blood Pressure:"), 
                value = ""),


      actionButton(inputId = "input_action", label = "Show Inputs")),



    mainPanel( 
      h2("Input Elements"), # title with HTML helper
      textOutput("td"))


  ))

但是我完全无法弄清楚如何将我在开头提到的 R 代码放入 server.R 文件中。我可以从简单地定义函数开始吗？然后如何对从用户处获取的输入运行该函数，然后将输出保存到每个变量中:age、cholestrol 和 bp???

服务器.R:

library(shiny)

#defining a function
rnorm2 <- function(n,mean,sd) { mean+sd*scale(rnorm(n)) }

shinyServer(function(input, output){

  #Don't know how run the function and save the output into the variables 
  age <- 
  cholestrol <- 
  bp <-  


  })

})

这是我使用 Shiny 的第一天，互联网上的所有 server.R 代码示例都让我难以理解。但我今天确实需要扭转局面。请帮忙!!!

Answer 1

我添加的唯一依赖项是library(DT)，这是一个非常有用的包。

您会注意到，您需要使输入 ID 在 ui.R 中唯一，并使用 eventReactive 指示 Shiny 等待输入按钮。

ui.R

library(shiny)
library(DT)
shinyUI(pageWithSidebar(
  headerPanel("function1"),

  sidebarPanel( 
    #Age input
    numericInput(inputId = "n", 
                 label = h4("Enter n:"), 
                 value = ""),

    numericInput(inputId = "mean1", 
                 label = h4("Enter mean for Age:"), 
                 value = ""),

    numericInput(inputId = "sd1", 
                 label = h4("Enter sd for Age:"), 
                 value = ""),

    #Cholestrol input        
    numericInput(inputId = "mean2", 
                 label = h4("Enter mean for Cholestrol:"), 
                 value = ""),

    numericInput(inputId = "sd2", 
                 label = h4("Enter sd for Cholestrol:"), 
                 value = ""),


    #Blood Pressure input
    numericInput(inputId = "mean3", 
                 label = h4("Enter mean for Blood Pressure:"), 
                 value = ""),

    numericInput(inputId = "sd3", 
                 label = h4("Enter sd for Blood Pressure:"), 
                 value = ""),


    actionButton(inputId = "input_action", label = "Show Inputs")),



  mainPanel( 
    h2("Input Elements"), # title with HTML helper
    dataTableOutput("inputs"),
    h2("Results"),
    dataTableOutput("results")
  )))

服务器.R

library(shiny)
library(DT)

rnorm2 <- function(n,mean,sd) { mean+sd*scale(rnorm(n)) }

shinyServer(function(input, output){

  data <- eventReactive(input$input_action, {
    matrix(
      c(rnorm2(input$n, input$mean1, input$sd1),
        rnorm2(input$n, input$mean2, input$sd2),
        rnorm2(input$n, input$mean3, input$sd3)), byrow = FALSE,
      ncol = 3)
  })

  inpts <- eventReactive(input$input_action, {
    data.frame(Type = c("Age", "Cholestorol", "BP"), 
               N = c(input$n, input$n, input$n),
               Mean = c(input$mean1, input$mean2, input$mean3),
               SD = c(input$sd1, input$sd2, input$sd3))
  }) 

  output$inputs <- renderDataTable({
    inpts()
  })
  output$results <- renderDataTable({
    set <- as.data.frame(data())
    colnames(set) <- c("Age", "BP", "Cholestorol")
    set
  })

})