r - Shiny R 上的工具提示？

Question

我想在我的 Shiny R 应用程序中添加工具提示。有什么简单的方法可以实现这一目标吗？现在，我正在创建一个密度图，我想要一个简单的工具提示，显示“单击此处滑动年份”，同时将鼠标悬停在 slider “年份”上。

用户界面:

library(shiny)
shinyUI(pageWithSidebar(
  headerPanel("Density Map"),
  sidebarPanel(
    sliderInput("slider_year", "YEAR:", 
                min = 2001, max = 2011, value = 2009, 
                format="####", locale="us"
    )
  )
 ),

  mainPanel(  
    plotOutput("event_heatmap_map", width = "100%", height = "100%")
  )
))

服务器代码:

library(shiny)
library(ggmap)
library(ggplot2)
mydata <- read.csv("/var/shiny-server/www/dMetrics.csv")
shinyServer(function(input, output) {
    output$event_heatmap_map <- renderPlot(width = "auto", height = 640,{

        slice_year <- mydata[mydata$YEAR==input$slider_year,]
        map <- get_map(c(lon = -55.3632715, lat = 31.7632836), zoom = 3, source = 'google', maptype = c("terrain"), messaging = FALSE, color = 'color')
        world <- ggmap(map)
        world <- world + stat_density2d(data = slice_year, aes(x = WEST, y = NORTH, fill = ..level.., alpha = ..level..), show_guide = FALSE, geom = "polygon", na.rm = TRUE) + scale_fill_gradient(name="Density", low="maroon", high="yellow", guide = 'colorbar')
        plot(world)
    })
})

感谢您的帮助。

Answer 1

我认为你应该能够替换这个:

sliderInput("slider_year", "YEAR:", 
            min = 2001, max = 2011, value = 2009, 
            format="####", locale="us"
)

这样:

tags$div(title="Click here to slide through years",
    sliderInput("slider_year", "YEAR:", 
                min = 2001, max = 2011, value = 2009, 
                format="####", locale="us"
    )
)