在 Shiny 中返回多个对象

Question

各位 R 用户您好我对 shiny 比较陌生，我正在尝试开发一个基本应用程序，它需要 4 只股票并打印最佳投资组合权重并绘制这些权重的图表。但是，我的应用程序仅打印最佳投资组合权重，而不是图表权重图。这是我的代码：

library(shiny)
library(PortfolioAnalytics)
library(quantmod)
library(PerformanceAnaltics)

server = function(input, output, session) {
  dsf=reactive({
    ticker<-c(input$stock1, input$stock2, input$stock3, input$stock4)
    portfolioPrice <- NULL
    for(ticker in ticker) {
      portfolioPrice <- cbind(portfolioPrice,
                              getSymbols.yahoo(ticker,  periodicity = 'daily', auto.assign=FALSE)[,6])
    }
    poty=na.omit(ROC(portfolioPrice))

    portf <- portfolio.spec(colnames(poty))
    portf <- add.constraint(portf, type="weight_sum", min_sum=.99, max_sum=1.01)
    portf <- add.constraint(portf, type="box", min=.02, max=.60) 
    portf<-add.constraint(portf,type="transation_cost", ptc=.001)
    portf <- add.objective(portfolio = portf, type="return", name="mean")
    portf <- add.objective(portfolio = portf, type="risk", name="StdDev")


    optPort <- optimize.portfolio(poty, portf, optimize_method = "random", trace=TRUE)
    ws=extractWeights(optPort)


    silf=chart.Weights(optPort)

    return(list(silf, ws))



  })



  output$wad<-renderPrint({
    dsf()
  })

  output$wadS<-renderPlot({
    dsf()
  })





} # the server

ui = basicPage(
  textInput("stock1", "stock1"),
  textInput("stock2", "stock2"),
  textInput("stock3", "stock3"),
  textInput("stock4", "stock4"),


  verbatimTextOutput("wad"),
  plotOutput("wadS")



) # the user interface

shinyApp(ui = ui, server = server) # perform app launch

这是应用程序的图片

如您所见，该应用采用 4 只股票和 returns 最佳投资组合权重，但它不仅应该打印最佳权重，而且还应该绘制权重图表。

像这样：

如何让我的应用程序获得 return 打印的重量和 return 我的图表重量图，非常感谢您的帮助

Answer 1

问题是您在 dsf 反应对象的列表中返回两个不同的对象，但您指定从该列表中呈现文本和绘图，这不会产生感觉。

最好的方法是将反应对象分解为单独的反应对象。尝试以下操作。在这里我设置它以便 dsf() 包含数据和两个单独的反应对象，ws 用于打印，silf 用于绘图：

library(shiny)
library(PortfolioAnalytics)
library(quantmod)
library(PerformanceAnaltics)

server <- function(input, output, session) {
  dsf <- reactive({
    ticker<-c(input$stock1, input$stock2, input$stock3, input$stock4)
    portfolioPrice <- NULL
    for(ticker in ticker) {
      portfolioPrice <- cbind(portfolioPrice,
                              getSymbols.yahoo(ticker,  periodicity = 'daily', auto.assign=FALSE)[,6])
    }
    poty=na.omit(ROC(portfolioPrice))

    portf <- portfolio.spec(colnames(poty))
    portf <- add.constraint(portf, type="weight_sum", min_sum=.99, max_sum=1.01)
    portf <- add.constraint(portf, type="box", min=.02, max=.60) 
    portf<-add.constraint(portf,type="transation_cost", ptc=.001)
    portf <- add.objective(portfolio = portf, type="return", name="mean")
    portf <- add.objective(portfolio = portf, type="risk", name="StdDev")


    optimize.portfolio(poty, portf, optimize_method = "random", trace=TRUE)
  })

  ws <- reactive({
    extractWeights(dsf())
  })


  silf <- reactive({
    chart.Weights(dsf())
  })

  output$wad<-renderPrint({
    ws()
  })

  output$wadS<-renderPlot({
    silf()
  })

  } # the server

ui = basicPage(
  textInput("stock1", "stock1"),
  textInput("stock2", "stock2"),
  textInput("stock3", "stock3"),
  textInput("stock4", "stock4"),


  verbatimTextOutput("wad"),
  plotOutput("wadS")

) # the user interface

shinyApp(ui = ui, server = server) # perform app launch

在 Shiny 中返回多个对象

Returning Multiple Objects in Shiny

r

shiny

shiny-server

quantitative-finance

shiny-reactivity