闪亮的R中有全局变量吗?-ArethereglobalvariablesinRShiny?

How do you declare global variables in with R Shiny so that you do not need to run the same pieces of code multiple times? As a very simple example I have 2 plots that use the same exact data but I only want to calculate the data ONCE.

如何在R中声明全局变量，从而不需要多次运行相同的代码片段?作为一个非常简单的例子，我有两个图使用相同的数据但是我只想计算一次数据。

Here is the ui.R file:

这是ui。R文件:

library(shiny)

# Define UI for application that plots random distributions 
shinyUI(pageWithSidebar(

# Application title
headerPanel("Hello Shiny!"),

# Sidebar with a slider input for number of observations
sidebarPanel(
sliderInput("obs", 
            "Number of observations:", 
            min = 1,
            max = 1000, 
            value = 500)
  ),

# Show a plot of the generated distribution
 mainPanel(
   plotOutput("distPlot1"),
  plotOutput("distPlot2")
 )
))

Here is the server.R file:

这是服务器。R文件:

library(shiny)

shinyServer(function(input, output) {

  output$distPlot1 <- renderPlot({ 
    dist <- rnorm(input$obs)
    hist(dist)
  })

  output$distPlot2 <- renderPlot({ 
    dist <- rnorm(input$obs)
    plot(dist)
  })

})

Notice that both output$distPlot1 and output$distPlot2 do dist <- rnorm(input$obs) which is re-running the same code twice. How do you make the "dist" vector run once and make it available to all the renderplot functions? I have tried to put the dist outside the functions like:

注意，输出$distPlot1和输出$distPlot2都dist <- rnorm(输入$obs)，它们正在重新运行相同的代码两次。如何使“dist”向量运行一次并使其对所有的renderplot函数都可用?我试过把区间放在函数之外，比如:

library(shiny)

shinyServer(function(input, output) {

  dist <- rnorm(input$obs)

  output$distPlot1 <- renderPlot({ 
    hist(dist)
  })

  output$distPlot2 <- renderPlot({ 
    plot(dist)
  })

})

But I get an error saying the "dist" object is not found. This is a toy example in my real code I have 50 lines of code that I am pasting into multiple "Render..." function. Any help?

但是我得到一个错误，说“dist”对象没有找到。这是我的真实代码中的一个玩具示例，我将50行代码粘贴到多个“呈现…”函数中。任何帮助吗?

Oh yea if you want to run this code just create a file and run this: library(shiny) getwd() runApp("C:/Desktop/R Projects/testShiny")

噢，如果你想运行这段代码，只要创建一个文件并运行它:library(闪亮的)getwd() runApp(“C:/Desktop/R Projects/ testbling”)

where "testShiny" is the name of my R studio project.

我的R studio项目的名字是“testbling”。

2 个解决方案

foo <<- runif(10)

foo <- runif(10)