将事件数据信息映射到 Shiny 反应图中的绘图信息

Question

如何从even_data信息中提取用于绘图的原始数据？

library(plotly)
library(shiny)

ui <- fluidPage(
  plotlyOutput("plot"),
  verbatimTextOutput("click")
)

server <- function(input, output, session) {

  output$plot <- renderPlotly({
    key <- row.names(mtcars)
    p <- ggplot(mtcars, aes(x = mpg, y = wt, colour = factor(vs), key = key)) + 
        geom_point()
    ggplotly(p) %>% layout(dragmode = "select")

  })


  output$click <- renderPrint({
    d <- event_data("plotly_click")
    if (is.null(d)) "Click events appear here (double-click to clear)" else d
  })


}

shinyApp(ui, server)

点击一个点时，示例输出类似于

  curveNumber pointNumber    x    y       key
1           1           3 24.4 3.19 Merc 240D

是否有任何方法可以将这些信息映射到原始数据集mtcars？ curveNumber、pointNumber 中的信息有何用处，这些字段的含义是什么？

Answer 1

curveNumber是colour = factor(vs)变量，pointNumber是组内的行号+1（vs的0或1）。

因此使用这两个您可以执行以下操作：

library(plotly)
library(shiny)
library(dplyr)
ui <- fluidPage(
  plotlyOutput("plot"),
  verbatimTextOutput("click")
)
server <- function(input, output, session) {
  output$plot <- renderPlotly({
    key <- row.names(mtcars)
    p <- ggplot(mtcars, aes(x = mpg, y = wt, colour = factor(vs), key = key)) + 
      geom_point()
    ggplotly(p) %>% layout(dragmode = "select")
  })
  output$click <- renderPrint({
    d <- event_data("plotly_click")
    if (is.null(d)) "Click events appear here (double-click to clear)" else mtcars %>% tibble::rownames_to_column() %>% filter(vs==d$curveNumber) %>% filter(row_number()==d$pointNumber+1)

  })
}
shinyApp(ui, server)

或者，第二个选项，您需要从 event_data 中提取 key 和子集 mtcars，如下所示：

output$click <- renderPrint({
    d <- event_data("plotly_click")
    if (is.null(d)) "Click events appear here (double-click to clear)" 
    else mtcars[rownames(mtcars) == d$key,]
  })

完整的应用程序：

library(plotly)
library(shiny)
ui <- fluidPage(
  plotlyOutput("plot"),
  verbatimTextOutput("click")
)
server <- function(input, output, session) {
  output$plot <- renderPlotly({
    key <- row.names(mtcars)
    p <- ggplot(mtcars, aes(x = mpg, y = wt, colour = factor(vs), key = key)) + 
      geom_point()
    ggplotly(p) %>% layout(dragmode = "select")
  })
  output$click <- renderPrint({
    d <- event_data("plotly_click")
    if (is.null(d)) "Click events appear here (double-click to clear)" else mtcars[rownames(mtcars) == d$key,]
  })
}
shinyApp(ui, server)

将事件数据信息映射到 Shiny 反应图中的绘图信息

Mapping the event data information to the plotting information in Shiny reactive plots

r

shiny

shinydashboard

shiny-reactivity