Update data frame of click data with user input

问题

I am new to shiny and would like to follow-up on one of my previous questions: Add reactive values from click events to existing data frame and update plot. I have updated the code but don't seem to understand how I should proceed. Till this point I managed with some help to make the app update an existing data frame with click data so that it plots and updates the regression line in the plot. Now I would like the user to have an option (I was thinking of radiobuttons) so that he can choose a class (-1/1) for those points he added with clicks. I don't know why I cant update the data frame with this third variable (the class) or even if I am going about it the right way.

 library(shiny)
    library(ggplot2)

    ui <- basicPage(
      plotOutput("plot1", click = "plot_click"),
      radioButtons("cls", "Clasa:", choices = list("Red" = -1, "Blue" = 1), selected = 1), 
      actionButton("refreshline", "Rline"),
      verbatimTextOutput("info")
    )

    server <- function(input, output) {

      x1 <- c(3, 10, 15, 3, 4, 7, 1, 12, 8, 18, 20, 4, 4, 5, 10)   #x
      x2 <- c(4, 10, 12, 17, 15, 20, 14, 3, 4, 15, 12, 5, 5, 6, 2) #y
      cls <- c(-1, 1, -1, 1, 1, 1, -1, 1, -1, 1, 1, 1, 1, -1, 1)   #class

      # initialize reactive values with existing data
      val <- reactiveValues( clickx = NULL, clicky = NULL, data = cbind (x1, x2, cls))

        observe({
        input$cls
        input$plot_click
        isolate({
          # save new points added
          val$clickx = c(val$clickx, input$plot_click$x)
          val$clicky = c(val$clicky, input$plot_click$y)

          # add new points to data                                              
          val$data <- rbind(val$data, cbind(input$plot_click$x, input$plot_click$y, as.numeric(input$cls)))
         })
  })


    output$plot1 <- renderPlot({
      p <- ggplot(data = NULL, aes(x=val$data[,1], y=val$data[,2], color = ifelse(val$data[,3] > 0, "Class 1","Class -1")))
      p <- p + geom_point()
      p <- p + xlab("x1")  
      p <- p + ylab("x2") 
     p <- p + scale_color_manual(name="Class Labels", values=c('#f8766d','#00BFC4'))
      p <- p + guides(color = guide_legend(override.aes = list(linetype = 0 )), 
                      linetype = guide_legend())
      p <- p + theme_bw() 
      p

      if(input$refreshline)
      p <- p + stat_smooth(method=lm)                         
      p

    })


      output$info <- renderText({
        input$plot_click
        paste0("x = ", val$clickx, ", y = ",val$clicky, "\n")
      })

    }

    shinyApp(ui, server)

回答1:

Take a look at this solution. It probably has still some work do to but it gives you a possible direction. I think that the observer that was reacting to two inputs was not a good solution since a change in any of them would add a row to val$data.

This is the modified code:

    library(shiny)
    library(ggplot2)

    ui <- basicPage(
            plotOutput("plot1", click = "plot_click"),
            radioButtons("cls", "Clasa:", choices = list("Red" = -1, "Blue" = 1), selected = 1), 
            actionButton("updateData", "Update data"),
            actionButton("refreshline", "Rline"),
            verbatimTextOutput("info"),
            verbatimTextOutput("data")
    )

    server <- function(input, output) {

            x1 <- c(3, 10, 15, 3, 4, 7, 1, 12, 8, 18, 20, 4, 4, 5, 10)   #x
            x2 <- c(4, 10, 12, 17, 15, 20, 14, 3, 4, 15, 12, 5, 5, 6, 2) #y
            cls <- c(-1, 1, -1, 1, 1, 1, -1, 1, -1, 1, 1, 1, 1, -1, 1)   #class

            # initialize reactive values with existing data
            val <- reactiveValues( clickx = NULL, clicky = NULL, data = cbind (x1, x2, cls))

            observeEvent(input$updateData, {
                    if (input$updateData > 0) {
                            val$data <- rbind(val$data, cbind(input$plot_click$x, input$plot_click$y, as.numeric(input$cls)))
                    }

            })
            observeEvent(input$plot_click, {
                    val$clickx = c(val$clickx, input$plot_click$x)
                    val$clicky = c(val$clicky, input$plot_click$y)  
            })        

            output$plot1 <- renderPlot({
                    p <- ggplot(data = NULL, aes(x=val$data[,1], y=val$data[,2], color = ifelse(val$data[,3] > 0, "Class 1","Class -1")))
                    p <- p + geom_point()
                    p <- p + xlab("x1")  
                    p <- p + ylab("x2") 
                    p <- p + scale_color_manual(name="Class Labels", values=c('#f8766d','#00BFC4'))
                    p <- p + guides(color = guide_legend(override.aes = list(linetype = 0 )), 
                                    linetype = guide_legend())
                    p <- p + theme_bw() 
                    p

                    if(input$refreshline)
                            p <- p + stat_smooth(method=lm)                         
                    p

            })


            output$info <- renderText({
                    input$plot_click
                    paste0("x = ", val$clickx, ", y = ",val$clicky, "\n")
            })
            output$data <- renderPrint({
                    val$data
            })

    }

    shinyApp(ui, server)

来源：https://stackoverflow.com/questions/39832436/update-data-frame-of-click-data-with-user-input