Question

我正在尝试制作一个可以读取.csv文件并在该应用程序中显示特定数据的闪亮应用程序。例如，如果我选择数字3并键入2，则“ H”将显示在应用程序中。

下面是示例代码：

library(shiny)
library(shinydashboard)
library(shinyWidgets)

ui = dashboardPage(
     dashboardHeader(title = "Selection"),
     dashboardSidebar(disable = TRUE), 
     dashboardBody(uiOutput("body")))



server = function (input, output, session) {

  output$body <- renderUI({ 
    box(numericInput('number', "Choose a number:", value = NULL, min = 1, max = 5),
        br(),
        selectInput('type', "Choose a type:", choices = list("Type 1", "Type 2")),
        br(),
        textOutput("my_selection"),
        br()

    )})


  selection_table <- reactive({read.csv("selection.csv", header = T, sep = "," , check.names = FALSE, col.names = TRUE)})


  output$my_selection = reactive({
    selection = ifelse(input$number == 1 & input$type == "Type 1", selection_table()$selection_1[1], 
                       ifelse(input$number == 2 & input$type == "Type 1", selection_table()$selection_1[2],
                              ifelse(input$number == 3 & input$type == "Type 1", selection_table()$selection_1[3],
                                     ifelse(input$number == 4 & input$type == "Type 1", selection_table()$selection_1[4],
                                            ifelse(input$number == 5 & input$type == "Type 1", selection_table()$selection_1[5],
                                                   ifelse(input$number == 1 & input$type == "Type 2", selection_table()$selection_2[1], 
                                                          ifelse(input$number == 2 & input$type == "Type 2", selection_table()$selection_2[2],
                                                                 ifelse(input$number == 3 & input$type == "Type 2", selection_table()$selection_2[3],
                                                                        ifelse(input$number == 4 & input$type == "Type 2", selection_table()$selection_2[4],
                                                                               ifelse(input$number == 5 & input$type == "Type 2", selection_table()$selection_2[5]))))))))))




    selection
  })

}
shinyApp(ui,server)

这是.csv文件中的示例数据：

age selection_1   selection_2
1    A             F
2    B             G
3    C             H
4    D             I
5    E             J

感谢任何帮助！！谢谢！

Answer 1

如果应用程序运行时csv中的数据没有动态更改，那么我会将read.csv移至标头，以便在应用程序启动时将其一次加载到内存中。

library(shiny)
library(shinydashboard)
library(shinyWidgets)

ui = dashboardPage(
     dashboardHeader(title = "Selection"),
     dashboardSidebar(disable = TRUE), 
     dashboardBody(uiOutput("body")))

df <- read.csv("selection.csv", header = T, sep = "," , check.names = FALSE, col.names = TRUE)

server = function (input, output, session) { #### ...rest of your app code

您嵌套的ifelse代码很复杂-尝试在csv中重命名数据可能会更容易，以便于子集设置，例如

output <- df[input1, input2]

...并将该子设置操作的输出传递到UI。

如何从.csv文件读取数据的特定列？

1 个答案: