使用selectInput()变量信息的分层sidebarLayout()

selectInput(inputId, label, choices, selected = NULL, multiple = FALSE, selectize = TRUE)

library(shiny)

ui <- fluidPage(
  sidebarLayout(
    sidebarPanel(
      selectInput("variable", "选择一个变量：",
                  choices = c("变量1", "变量2", "变量3"),
                  selected = "变量1")
    ),
    mainPanel(
      plotOutput("plot")
    )
  )
)

server <- function(input, output) {
  output$plot <- renderPlot({
    # 根据用户选择的变量绘制相应的图形
    if (input$variable == "变量1") {
      plot(1:10, main = "变量1")
    } else if (input$variable == "变量2") {
      plot(1:10, main = "变量2")
    } else if (input$variable == "变量3") {
      plot(1:10, main = "变量3")
    }
  })
}

shinyApp(ui, server)