使用閃亮創建一個期權定價的應用程序，它爲什麼一直顯示「未subsettable類型的對象‘關閉’」

Question

爲什麼會不斷出現：

「類型的對象‘關閉’不是subsettable」

library(shiny) 
    ui<-fluidPage(
     numericInput(inputId = "S0",label = "price at time 0",value = 20), 
     numericInput(inputId = "k",label = "exercise price",value = 20), 
     numericInput(inputId = "N",label = "steps",value = 50), 
     numericInput(inputId = "r",label = "riskfree rate",value = 0.03), 
     numericInput(inputId = "t",label = "time to exercise data",value = 1), 
     plotOutput(outputId = "v") 
    ) 

server<-function(input,output) 
{ 
    for(i in 2:246)  # 246 days data 
    zsp$r[i]=log(zsp$ZSP[i]/zsp$ZSP[i-1]) 
    bzc=sd(zsp$r) 
    sigma=bzc*sqrt(246)#volatility 

    ve<-reactive({vector(mode="numeric",length=input$N+1)}) 

    u<-reactive({exp(sigma*sqrt(input$t/input$N)) }) 

    d<-reactive({1/u}) 

    p<-reactive({(exp(input$r*input$t/input$N)-d)/(u-d)}) 

    ve<-reactive({rep(input$N,9)}) 




    for(i in 1:51) #origin vector for options at time 1 
    { 
    ve[i]<-reactive({max(0,(input$S0*d^(i-1)*u^(input$N-i+1)-input$k))}) 
    } 
    for(m in 50:1) 
    { 
    for(j in 1:m) 
    { 
     ve[j]<-reactive({(ve[j]*p+ve[j+1]*(1-p))*exp(-input$r*input$t/input$N)}) 
    } 
    } 

output$v<-renderPlot({plot(ve())}) 

} 




shinyApp(ui=ui,server=server) 

Answer 1

你for loops必須被包裹在一個反應​​。所有服務器端代碼必須被包裹在shiny功能，如reactive，renderPlot等

的這部分代碼應爲：

output$v<-renderPlot({   
      for(i in 1:51) #origin vector for options at time 1 
      { 
      ve[i]<-max(0,(input$S0*d^(i-1)*u^(input$N-i+1)-input$k)) 
      } 
      for(m in 50:1) 
      { 
      for(j in 1:m) 
      { 
       ve[j]<-(ve[j]*p+ve[j+1]*(1-p))*exp(-input$r*input$t/input$N) 
      } 
      } 
    plot(ve()) 

})