正确的论证方式

Question

我的目标是制作一个包含条形图的闪亮应用，其参数从selectInput中读取。 我一直收到错误：＆＃34; Error in eval(expr, envir, enclos) : object 'input' not found＆＃34;。 我也尝试过，正如Ramnath所说：f = as.formaula(~ input$x)但没有任何效果。 任何帮助将不胜感激。

我的代码：

require(rCharts)
require(shiny)
aw<- read.table("G:\\Research - LPvsTW\\Text fIles\\LpIntw.txt", header = TRUE, sep = "\t", fill = TRUE)
shinyServer(function(input, output) {

  output$myChart <- renderChart2({
    f = as.formula(~ input$x)

    p1 <- nPlot(f , group = "input$y" , data = aw, type = 'multiBarChart')


    p1$addParams(dom = 'myChart')
    return(p1)
  })
})
#################################
require(rCharts)
require(shiny)
aw<- read.table("G:\\Research - LPvsTW\\Text fIles\\LpIntw.txt", header = TRUE, sep = "\t", fill = TRUE)
shinyUI(pageWithSidebar(
  headerPanel("rCharts: Interactive Charts from R using polychart.js"),

  sidebarPanel(
    selectInput(inputId = "x",
                label = "Choose X",
                choices = names(aw),
                selected = "SecQof"),
    selectInput(inputId = "y",
                label = "Group by",
                choices = names(aw),
                selected = "Gender")
  ),
  mainPanel(
    showOutput("myChart", "nvd3")
  )
))