R Shiny Reactive 值，dplyr 过滤器错误？

Question

我正在尝试弄清楚 select 在 UI 中输入以立即在页面上反映结果。我的搜索结果让我研究了反应性表达和反应性价值。但是当我试图过滤数据的值时，我认为这会导致一些复杂情况，但我不知道我应该用它做什么。

虽然过滤功能似乎不起作用。

这是错误信息：

Warning: Error in UseMethod: no applicable method for 'filter_' applied to an object of class "c('reactiveExpr', 'reactive')"
Stack trace (innermost first):
    51: filter_
    50: filter.default
    49: filter
    48: function_list[[i]]
    47: freduce
    46: _fseq
    45: eval
    44: eval
    43: withVisible
    42: %>%
    41: eval
    40: makeFunction
    39: exprToFunction
    38: observe
    37: server 
     1: runApp
Error in UseMethod("filter_") : 
  no applicable method for 'filter_' applied to an object of class "c('reactiveExpr', 'reactive')"

Answer 1

我发现了两个问题，

第一个反应语句是函数 - 您需要在它们之后添加方括号 ()。其次，您需要处理变量的命名，尤其是在 R 中命名变量 data 从来都不是一件好事，并且您首先将两个对象命名为相同的数据集本身，其次是返回数据集的反应式语句——看来这个糊涂闪亮了不少。我将反应语句重命名为 dta 并为我解决了它。这是完整的服务器代码

server <- function(input, output, session) {

  dta <- reactive({
    data
  })

  output$p1 <- renderText({
    paste0("You currently live in ", input$Location, " and are contemplating a job offer in ", input$reLocation, ".")
  })

  values <- reactiveValues()
  observe({ 
    # req(input$Location,input$reLocation)
    # browser()
    values$LocationCost <-  dta() %>% filter(UrbanArea == input$Location) %>% select(CostOfLivingIndex)
    values$reLocationCost <-  dta() %>% filter(UrbanArea == input$reLocation) %>% select(CostOfLivingIndex)
  }) 
  # observeEvent(input$Location, {
  #   values$LocationCost <- data %>%
  #     filter(UrbanArea == input$Location) %>%
  #     select(CostOfLivingIndex)
  # })
  # 
  # observeEvent(input$reLocation, {
  #   values$reLocationCost <- data %>%
  #     filter(UrbanArea == input$reLocation) %>%
  #     select(CostOfLivingIndex)
  # })

  output$p2 <- renderText({
    if (values$LocationCost < values$reLocationCost) {
      calc <- round(100* ((values$reLocationCost-values$LocationCost)/values$LocationCost), 2)
      print(paste0("You need ", calc, "% increase in your after-taxes income in order to maintain your present lifestyle."))
    } else {
      calc <- round(100 * ((values$LocationCost-values$reLocationCost)/values$reLocationCost), 2)
      print(paste0("You can sustain upto ", calc, "% reduction in after taxes income without reducing your present lifestyle."))
    }
  })


}

希望对您有所帮助！！

R Shiny Reactive 值，dplyr 过滤器错误？

R Shiny Reactive values, dplyr filter error?

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