使用现有绘图在shiny中创建下拉图

install.packages("shiny")

library(shiny)

ui <- fluidPage(
  titlePanel("下拉图示例"),
  sidebarLayout(
    sidebarPanel(
      selectInput("plotType", "选择图表类型：",
                  choices = c("散点图", "折线图", "柱状图"),
                  selected = "散点图")
    ),
    mainPanel(
      plotOutput("plot")
    )
  )
)

server <- function(input, output) {
  output$plot <- renderPlot({
    if (input$plotType == "散点图") {
      plot(mtcars$mpg, mtcars$hp, main = "散点图示例", xlab = "汽车每加仑英里数", ylab = "汽车马力")
    } else if (input$plotType == "折线图") {
      plot(mtcars$mpg, mtcars$disp, main = "折线图示例", xlab = "汽车每加仑英里数", ylab = "汽车排量")
    } else if (input$plotType == "柱状图") {
      barplot(mtcars$mpg, main = "柱状图示例", xlab = "汽车", ylab = "汽车每加仑英里数")
    }
  })
}

shinyApp(ui, server)