為什么在嘗試使用 R Shiny 和 networkD3 制作桑基圖時會出現“缺少參數”輸出，沒有默認值”？

Question

我正在嘗試通過 networkD3 示例在 R 中制作一個閃亮的應用程序。 我的代碼附在底部。

我從這個頁面得到了代碼。

當我嘗試運行它時，我收到此錯誤消息：

Error in shinyServer(function(input, output) { : 
  argument "output" is missing, with no default

問題：如何修復代碼以使其工作？

library(shiny)
library(networkD3)
data(MisLinks)
data(MisNodes)

shinyUI(fluidPage(

  titlePanel("Shiny networkD3 "),

  sidebarLayout(
    sidebarPanel(
      numericInput("opacity", "Opacity", 0.6, min = 0.1, max = 1, step = .1)
    ),
    mainPanel(
      tabsetPanel(
        tabPanel("Simple Network", simpleNetworkOutput("simple")),
        tabPanel("Force Network", forceNetworkOutput("force")),
        tabPanel("Force Network with Legend & Radius", forceNetworkOutput("forceRadius")),
        tabPanel("Sankey Network", 
                 checkboxInput("sinksRight", "sinksRight", value = TRUE),
                 sankeyNetworkOutput("sankey")),
        tabPanel("Reingold-Tilford Tree", radialNetworkOutput("rt"))
      )
    )
  )
))

shinyServer(function(input, output) {


  output$sankey <- renderSankeyNetwork({
    URL <- "https://cdn.rawgit.com/christophergandrud/networkD3/master/JSONdata/energy.json"
    Energy <- jsonlite::fromJSON(URL)
    sankeyNetwork(Links = Energy$links, Nodes = Energy$nodes, Source = "source",
                  Target = "target", Value = "value", NodeID = "name",
                  fontSize = 12, nodeWidth = 30, sinksRight = input$sinksRight)
  })



})

shinyApp(ui, server)

Answer 1

您應該將您的UI分配給 ui，並將您的server功能分配給一個名為server的變量。 然后將它們作為參數傳遞到最后一行shinyApp(ui,server) 。 希望這可以幫助！

工作代碼：

library(shiny)
library(networkD3)
data(MisLinks)
data(MisNodes)

ui <- shinyUI(fluidPage(

  titlePanel("Shiny networkD3 "),

  sidebarLayout(
    sidebarPanel(
      numericInput("opacity", "Opacity", 0.6, min = 0.1, max = 1, step = .1)
    ),
    mainPanel(
      tabsetPanel(
        tabPanel("Simple Network", simpleNetworkOutput("simple")),
        tabPanel("Force Network", forceNetworkOutput("force")),
        tabPanel("Force Network with Legend & Radius", forceNetworkOutput("forceRadius")),
        tabPanel("Sankey Network", 
                 checkboxInput("sinksRight", "sinksRight", value = TRUE),
                 sankeyNetworkOutput("sankey")),
        tabPanel("Reingold-Tilford Tree", radialNetworkOutput("rt"))
      )
    )
  )
))

server <- function(input, output) {


  output$sankey <- renderSankeyNetwork({
    URL <- "https://cdn.rawgit.com/christophergandrud/networkD3/master/JSONdata/energy.json"
    Energy <- jsonlite::fromJSON(URL)
    sankeyNetwork(Links = Energy$links, Nodes = Energy$nodes, Source = "source",
                  Target = "target", Value = "value", NodeID = "name",
                  fontSize = 12, nodeWidth = 30, sinksRight = input$sinksRight)
  })



}

shinyApp(ui, server)