在R with with Shiny中将日期从“闭包”类型强制转换为“double”类型？

Question

我正在使用Shiny

编写一个3D股票投资组合模型

ui.R是：

# UI

# Libraries
library(shiny)

# Interface
shinyUI(fluidPage(
 titlePanel("3D Stock Projection"),

 sidebarLayout(
    sidebarPanel(
            helpText("Select a stock to examine. 
        Information will be collected from yahoo finance."),

            textInput("symb", "Symbol", "SPY"),

            dateRangeInput("dates",
                "Date range",
                start = "2013-01-01",
                end = as.character(Sys.Date())),

            actionButton("get", "Get Stock"),

            br(),
            br(),

          checkboxInput("log", "Plot y axis on log scale",
                value = FALSE),

            checkboxInput("adjust", "Adjust prices for inflation", 
            value = FALSE)
        ),

    mainPanel(plotOutput("plot"))
 )
 ))

server.R是：

# Server 

# Libraries
 library(shiny)
 library(TTR)
 library(scales)
 library(quantmod)
 library(scatterplot3d)

#Equations
 shinyServer(function(input, output) {

 #This finds holding period
  time <- reactive({
    getSymbols(input$symb, 
        src="yahoo", 
            from = input$dates[1],
            to = input$dates[2],
            auto.assign = FALSE)
  })

 #Basic yield equaition in percentage
  yield <- reactive({
    initial <- as.number(getQuote(input$symb,
            src="yahoo",
            from = input$date[1],
            auto.assign = FALSE)
        )
    final <- as.number(getQuote(input$symb, 
            src="yahoo",
            from = input$date[2],
            auto.assign = FALSE)
        )       
    as.number(percent(((final-initial)/initial)))
  })

 #This finds the alpha by retrieving the S&P yield  
  alpha <- reactive({
    marketInitial <- as.number(getQuote("S&P500",
                src="yahoo",
                from = input$date[1],
                auto.assign = FALSE)
            )
    marketFinal <- as.number(getQuote("S&P500",
                src="yahoo",
                from = input$date[2],
                auto.assign = FALSE)
            )
    as.number(percent(((marketFinal-marketInitial)/marketInitial)))     
  })    

 #3D Projection         
  output$plot <- renderPlot({
    scatterplot3d(time, yield, alpha, 
            highlight.3d = TRUE,
            col.axis = "blue",
            col.grid = "ligthblue",
            main = "Helix",
            pch = 20)
  })
 })

当我运行它时，界面打开成功，但情节不会出现，而是它给我一个错误，说我不能＆＃34; 强制类型＆＃39;关闭＆＃ 39;到＆＃39; double＆＃39; ＆＃34;

的矢量

我认为问题是日期系统和我计算时间的方式，这很困难，因为我必须管理日期而不是数字，而且Stackoverflow上的这个问题的其他任何实例都没有解决关闭问题复杂的约会。

我想提前感谢大家的帮助XD