反应变化最小/最大范围+ 2个数据帧闪亮

我的 Shiny 应用程序有一个问题。首先，我有两个dataframes其中有两个numeric列 （number and number2）。我也有动态用户界面sliderInput。闪亮的应用程序工作正常，直到...当我选择时Item数据框，选择number in Y-axis variable并设置range in sliderInput之间，例如15和18，之后我想改变Y-axis variable to number2我收到错误：
Error in eval(substitute(expr), envir, enclos) : wrong result size (2), expected 0 or 1
我知道这个问题是因为数字引起的number2列介于 1 和 10 之间，之前的设置不包括该数字。谁能告诉我如何改进它？

ui.R

library(ggvis)

shinyUI(fluidPage(

titlePanel(""),

sidebarLayout(
 sidebarPanel(
  radioButtons("dataset", label = h4("Choose dataframe"),
               choices = list("Item" = "df1", "Task" = "df2")),
   selectInput("yvar", "Y-axis variable", axis_vars_y, selected = "number"),
   uiOutput("slider")
   ),
mainPanel(
  ggvisOutput("plot")
  )
 )
))

server.R

library(shiny)
library(dplyr)
library(magrittr)
library(lazyeval)

df1_number <-sample(seq(1,20,0.01),20,replace = T)
df2_number <-sample(seq(1,20,0.01),20,replace = T)
df1_number2 <-sample(seq(1,10,0.01),20,replace = T)
df2_number2 <-sample(seq(1,10,0.01),20,replace = T)

df1 <- data.frame(name = rep(letters[1:4],each = 5), number = df1_number, number2 = df1_number2)
df2 <- data.frame(name = rep(letters[1:4],each = 5), number = df2_number, number2 = df2_number2)
axis_vars_y <- c("number" = "number", "number2" = "number2")



shinyServer(function(input, output) {

  datasetInput <- reactive({
    switch(input$dataset,
           df1 = df1,
           df2 = df2)
  })

  axis_vara_y <- reactive({
    switch(input$yvar,
           number = 2,
           number2 = 3)
  }) 

    output$slider <- renderUI({
      sliderInput("inslider","Slider", min   = min(datasetInput()[,axis_vara_y()]), 
                                       max   = max(datasetInput()[,axis_vara_y()]),
                                       value = c(min(datasetInput()[,axis_vara_y()]), 
                                                 max(datasetInput()[,axis_vara_y()])),
                                       step = 0.5)
})

  data <- reactive({
    filteredData <- datasetInput()
    if(!is.null(input$inslider)){
      filteredData <- filteredData %>%
        filter(filteredData[,axis_vara_y()] >= input$inslider[1],
               filteredData[,axis_vara_y()] <= input$inslider[2])
    }
    filteredData
})

  data_two <- reactive({
    data() %>%
      mutate(id = 1:n())

  })  

  vis <- reactive({

    yvar_name <- names(axis_vars_y)[axis_vars_y == input$yvar]
    yvar <- prop("y", as.symbol(input$yvar))

    data_two %>%
      ggvis(x = ~name, y = yvar) %>%    
      layer_points(size := 120,
                     fill = ~name,
                     fillOpacity := 0.6, 
                     key := ~id)

      })
      vis %>% bind_shiny("plot")
    })

Update-------------------------------------------------- -------------------------------------------------

相同error当我设置的范围不包含任何值时会发生number列（例如 13 到 14 之间）。

正如您所意识到的，您收到错误是因为过滤后的数据集没有行。一个简单的解决方法是返回完整的数据集。这将重置inputSlider以便您继续工作而不会出现错误。你只需要改变你的反应data功能。

data <- reactive({
  filteredData <- datasetInput()
  axisData <- axis_vara_y()

  if(!is.null(input$inslider)){
    filteredData <- filteredData %>%
      filter(filteredData[,axisData] >= input$inslider[1],
             filteredData[,axisData] <= input$inslider[2])
  }

  # the new part to reset the slider
  if(nrow(filteredData) == 0){
    return(datasetInput())
  }else{
    return(filteredData)
  }
})

我冒昧地稍微简化了代码，因为您可以分配反应性数据语句，而不会让闪亮的应用程序多次调用它们。