如何从闪亮的点击中获取x类别

Posted 2023-02-16

【中文标题】如何从闪亮的点击中获取x类别

【英文标题】：How to get x category from click in shiny

【发布时间】：2021-11-29 19:24:03

【问题描述】：

如何通过单击闪亮的条形图从条形图中获取类别（x 轴信息）。请参阅下面的应用程序。我希望 output$cut 在用户单击图中的一个条时显示 cut 类型。

library(shiny)
library(ggplot2)
library(dplyr)

ui <- fluidPage(
  plotOutput('diamonds', click = "click"),
  textOutput('cut')
)

server <- function(input, output, session) 
  output$diamonds <- renderPlot(
    diamonds %>% 
      ggplot() +
      geom_bar(aes(cut))
  )
  
  output$cut <- renderText(
    req(input$click)
    
    # This isn't meaningful
    x <- round(input$click$x, 2)
    y <- round(input$click$y, 2)
    cat("[", x, ", ", y, "]", sep = "")
    
    # and this doesn't work either
    # nearPoints(diamonds, input$click, xvar = "cut")
  )


shinyApp(ui, server)

【参考方案1】：

您从input$click$x 获得的 x 值对应于被点击的因子。这需要四舍五入为整数，可用于获取因子名称。

因子名称可用于过滤diamonds 数据集。

x <- round(input$click$x) ## this will return a whole number corresponding to the factor that was clicked on.

##filter for the selected cut by using levels to get the name of the factor.
selected_cut <- diamonds %>% filter(cut == levels(diamonds$cut)[x])