基于 selectInput 的 ggplot2 和 Shiny 条件美学？答案

【问题标题】：ggplot2 and Shiny conditional aesthetics based on selectInput?基于 selectInput 的 ggplot2 和 Shiny 条件美学？
【发布时间】：2021-01-13 12:57:09
【问题描述】：

我已经构建了一个闪亮的仪表板，其中一部分将允许人们生成与其地理区域相关的图表。区域将作为 selectInput 列在侧栏中，并在图表上绘制区域，但是，如果他们选择英格兰，我希望它具有不同的美感，尤其是更粗的线，以便突出。所有其他区域的厚度应相同，但颜色仍应不同，以便区分。我觉得我错过了一些非常明显的东西！

  dashboardHeader(title = "Dashboard"
  ),
  dashboardSidebar(
    sidebarMenu(id = "sidebarid", 
                               menuItem("Graphs", tabName = "graphs", icon = icon("chart-line")),
                               conditionalPanel(
                                 'input.sidebarid == "graphs"',
                                 selectInput("area", "Area",
                                             c("England", "Bolton","Bury","Manchester","Oldham", "Rochdale", "Salford","Stockport","Tameside","Trafford","Wigan"),
                                             multiple = T, selected = "Manchester")
                               )
                   )
  ),
  dashboardBody(
    ## Maps Tab, core dashboard
      tabItem(
        tabName = "graphs",
        fluidRow(
          width = "100%",
          plotOutput("chart"),
        )
      )
    )
  )

server <- 
  
  function(input,output, session){
    
    area <- reactive({
      NCMPRec_time %>% filter(AreaName %in% input$area)
    })
    
    output$chart <- renderPlot({
      ggplot(area(), aes(x=Timeperiod, y=Value, group = AreaName)) +
        geom_line(aes(color = AreaName)) +
        geom_point(aes(color = AreaName)) +
        labs(x = "Time", y = "Percent", col="Area") +
        theme_classic() +
        scale_colour_branded()
    })
    

  }

shinyApp(ui, server)

【问题讨论】：

标签： r ggplot2 shiny

【解决方案1】：

您可以使行大小取决于input$area：

output$chart <- renderPlot({
      if (input$area == "England") {
        line_size <- 1
      } else {
        line_size <- 0.5
      }
      
      ggplot(area(), aes(x=Timeperiod, y=Value, group = AreaName)) +
        geom_line(aes(color = AreaName), size = line_size) +
        geom_point(aes(color = AreaName)) +
        labs(x = "Time", y = "Percent", col="Area") +
        theme_classic() +
        scale_colour_branded()
    })

【讨论】：