如何在 Shiny 中将 fileInput 连接到 ggplot？

Question

我今天已经为此工作了 6 个多小时，我知道这是一个简单的问题，但我无法弄清楚。我想要的是输入一个文件，然后能够使用多个 selectInput 下拉菜单来更改 ggplot 上的输出。这是我目前所拥有的：

用户界面：

ui = dashboardPage(
  dashboardHeader(title = "Apple Financials"),
  dashboardSidebar(
    fileInput("file1", label = "Upload SAS Data:", accept = ".sas7bdat"),
    selectInput("x", label = "X-Axis Variable", choices = c("Sales", "Cash", "Assets", "Profits", "R&D", "SG&A")),
    selectInput("y", label = "Y-Axis Variable", choices = c("Sales", "Cash", "Assets", "Profits", "R&D", "SG&A"), selected = "R&D"),
    selectInput("scale", label = "Choose the Scale:", choices = c("Levels", "Log 10")),
    radioButtons("model", label = "Choose the Model:", choices = c("Linear Model", "LOESS", "Robust Linear", "None"), selected = "LOESS"),
    checkboxInput("ribbon", label = "Standard Error Ribbon", value = TRUE),
    conditionalPanel(
      condition = "input.model == 'LOESS'",
      sliderInput("span", label = "Span for LOESS", min = 0, max = 1, value = .75)
    )
  ),
  dashboardBody(
    box(width = NULL, height = 415, plotOutput("plots"))
  )
)

服务器：

server = function(input, output) {


   observe({
     data = input$file1
      if(is.null(data))
      return(NULL)

    df = read_sas(data$datapath)
    output$plots = renderPlot({
    ggplot(df, aes(x = input$x, y = input$y)) +
      geom_line()
   })
 })
}

Answer 1

由于输入是字符串，我们需要aes_string in ggplot

server = function(input, output) {


  observe({
    data = input$file1
    if(is.null(data))
      return(NULL)

    df = read_sas(data$datapath)
    output$plots = renderPlot({
      ggplot(df, aes_string(x = input$x, y = input$y)) +
        geom_line()
    })
  })
}
shinyApp(ui, server)

注意：为了演示，我们上传的是 csv 文件而不是 SAS 文件