Using Proxy Interface in Plotly/Shiny to dynamically change data

问题

I want to update the data present in a plot (displayed in plotlyOutput in a Shiny app) using Proxy Interface. Here is a minimal App.R code :

library(shiny)
library(plotly)

ui <- fluidPage(
    actionButton("update", "Test"),
    plotlyOutput("graphe")
)

server <- function(input, output, session) {
    output$graphe <- renderPlotly({
        p <- plot_ly(type="scatter",mode="markers")
        p <- layout(p,title="test")
        p <- add_trace(p, x=0,y=0,name="ABC_test",mode="lines+markers")
    })

    observeEvent(input$update, {
        proxy <- plotlyProxy("graphe", session) %>%
            plotlyProxyInvoke("restyle", list(x=0,y=1),0)
    })
}

shinyApp(ui, server)

When I run it, the plot is displayed with a dot at (0,0) (as wanted) but when I click of the button "Test", the dot does not move to (0,1). How can I achieve this ?

Thank you for any answer.

回答1:

Strangely enough addTracesdoes not work with only one point but works with two points. To make it work you could add the same point twice. So you could try this:

ui <- fluidPage(
  actionButton("update", "Test"),
  plotlyOutput("graphe")
)

server <- function(input, output, session) {
  output$graphe <- renderPlotly({
    p <- plot_ly(type="scatter",mode="markers")
    p <- layout(p,title="test")
    p <- add_trace(p, x=0,y=0,name="ABC_test",mode="lines+markers")
  })

  observeEvent(input$update, {
    plotlyProxy("graphe", session) %>%
    plotlyProxyInvoke("deleteTraces", list(as.integer(1))) %>%
    plotlyProxyInvoke("addTraces", list(x=c(0, 0),y=c(1, 1),
                        type = 'scatter',
                        mode = 'markers'))
  })
}

shinyApp(ui, server)

回答2:

The restyle API is a bit wonky...I forget the reasoning, but data arrays like x and y need double arrays. I'd do it this way:

library(shiny)
library(plotly)

ui <- fluidPage(
  actionButton("update", "Test"),
  plotlyOutput("graphe")
)

server <- function(input, output, session) {
  output$graphe <- renderPlotly({
    plot_ly() %>%
      add_markers(x = 0, y = 0, name = "ABC_test") %>%
      layout(title = "test")
  })

  observeEvent(input$update, {
    plotlyProxy("graphe", session) %>%
      plotlyProxyInvoke("restyle", "y", list(list(1)), 0)
  })
}

shinyApp(ui, server)

回答3:

library(shiny)

ui <- fluidPage(
    actionButton("update", "Test"),
    plotlyOutput("graphe")
)

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

    output$graphe <- renderPlotly({
        plot_ly() %>%
            layout(title="test") %>%
            add_trace(x=runif(2), y=runif(2), name="ABC_test", type="scatter", mode="lines+markers")
    })

    observeEvent(input$update, {
        plotlyProxy("graphe", session, FALSE) %>%
            plotlyProxyInvoke("deleteTraces", list(as.integer(0))) %>%
            plotlyProxyInvoke("addTraces", list(x=runif(2),
                                                y=runif(2),
                                                name="ABC_test",
                                                type = 'scatter',
                                                mode = 'lines+markers'))
    })

}

shinyApp(ui, server)

来源：https://stackoverflow.com/questions/50620360/using-proxy-interface-in-plotly-shiny-to-dynamically-change-data

标签

Shiny

r-plotly