发布到shinyappio时app.R运行应用程序本地主机错误已解决

Question

我遵循 Kunaal Naik 的 Shiny_Dashboards 反应式示例，并尝试重现一个更简单的数据集，但出现映射错误，“美学必须是长度 1 或与数据 (1): x 相同”。我做错了什么？

server <- function(input, output, session) {
  
SalesRep <- c("Amy","Amy", "Amy", "Joe", "Joe", "Joe")
QTR <- c("Q1", "Q2", "Q3", "Q1", "Q2", "Q3")
Sales <- c(10, 20, 30, 5, 10, 15)
sales <- data.frame(SalesRep, QTR, Sales)

  #Summarize Data and then Plot
  data <- reactive({
    req(input$sel_SalesRep)
    df <- sales %>% filter(SalesRep %in% input$sel_SalesRep) %>%  group_by(QTR) %>% summarise(Sales = sum(Sales))
  })
  
  #Plot 
  output$plot <- renderPlot({
    g <- ggplot(data(), aes(y = Sales, x = QTR))
    g + geom_bar(stat = "sum")
  })
}

ui <- basicPage(
  h1("R Shiny interactive Bar Chart using Reactive and Render"),
  selectInput(inputId = "sel_SalesRep",
              label = "Choose Sales Rep",
              list("Amy","Joe")),
  plotOutput("plot")
)

shinyApp(ui = ui, server = server)