带有传单的闪亮选择范围和数字变量（作为输入）

Question

在闪亮时，我想显示一个数值变量列表和一个滑动条，以便用户可以选择一个数值变量和一个范围。然后，低于该数字的观测值将显示为绿色，该范围之间的观测值将显示为橙色，高于该范围的观测值将显示为红色。

在我将它们放入闪亮之前，下面的代码可以正常工作。但是我的闪亮代码不起作用，所有观察结果都是红色的。

library(Rcpp)
library(ggmap)
library(htmlwidgets)
library(leaflet)

crime2 <- crime[1:50,]

getColor <- function(crime2) {
 sapply(crime2$hour, function(hour) {
 if(hour< 1) {
   "green"
 } else if(hour <= 1) {
   "orange"
 } else {
   "red"
  } })
}

icons <- awesomeIcons(
  icon = 'ios-close',
  iconColor = 'black',
  library = 'ion',
  markerColor = getColor(crime2)
)

leaflet(crime2) %>%
  addTiles() %>%
  addAwesomeMarkers(~lon, ~lat, icon=icons)

这是不起作用的闪亮代码

ui <- fluidPage(
  titlePanel("Unusual Observations"),

  sidebarLayout(
    sidebarPanel(
      helpText("Create maps with 
        information from the Crime Data"),

      selectInput("var", 
                  label = "Choose a variable to display",
                  choices = c("Hour",
                              "Number"),
                  selected = "Hour"),

      sliderInput("range", 
                  label = "Range of interest:",
                  min = 0, max = 10, value = c(1, 2))
    ),

    mainPanel(leafletOutput("map"))
  )
)


server <- function(input, output) {
  output$map <- renderLeaflet({
    data <- switch(input$var,
                   "hour" = crime2$hour,
                   "number" = crime2$number)

    getColor <- function(data){sapply(data, function(var){
       if(input$var< input$range[1]) {
         "green"
       } else if(input$var <= input$range[2]) {
         "orange"
       } else {
         "red"
        } })
    }

  icons <- awesomeIcons(
  icon = 'ios-close',
  iconColor = 'black',
  library = 'ion',
  markerColor = getColor(crime2)
)

    leaflet(crime2) %>%
  addTiles() %>%
  addAwesomeMarkers(~lon, ~lat, icon=icons)

  })
}

shinyApp(ui=ui, server=server)

有人知道如何解决“所有点都显示为红色”的问题吗？

提前感谢您！

Answer 1

一些变化：

1. 当您创建 selectInput 时，选项（和选定的）需要小写以匹配犯罪 2 中的列名。

   selectInput("var", 
                 label = "Choose a variable to display",
                 choices = c("hour",
                             "number"),
                 selected = "hour"),
   

2. 在 getColor 函数内部，您希望循环遍历 data 中的值，而不是 input$var，因此您应该在 lambda 函数内部调用 var 而不是 input$var。

   getColor <- function(data){sapply(data, function(var){
         if(var< input$range[1]) {
           "green"
         } else if(var <= input$range[2]) {
           "orange"
         } else {
           "red"
         } })
       }
   

3. 当您实际创建图标时，您希望它们是基于 data 中的值创建的，而不是整个犯罪 2 数据集中的值。

   icons <- awesomeIcons(
         icon = 'ios-close',
         iconColor = 'black',
         library = 'ion',
         markerColor = getColor(data)
       )
   

把它们放在一起：

ui <- fluidPage(
  titlePanel("Unusual Observations"),

  sidebarLayout(
    sidebarPanel(
      helpText("Create maps with 
        information from the Crime Data"),

      selectInput("var", 
                  label = "Choose a variable to display",
                  choices = c("hour",
                              "number"),
                  selected = "hour"),

      sliderInput("range", 
                  label = "Range of interest:",
                  min = 0, max = 10, value = c(1, 2))
    ),

    mainPanel(leafletOutput("map"))
  )
)


server <- function(input, output) {
  output$map <- renderLeaflet({
    data <- switch(input$var,
                   "hour" = crime2$hour,
                   "number" = crime2$number)

    getColor <- function(data){sapply(data, function(var){
      if(var< input$range[1]) {
        "green"
      } else if(var <= input$range[2]) {
        "orange"
      } else {
        "red"
      } })
    }

    icons <- awesomeIcons(
      icon = 'ios-close',
      iconColor = 'black',
      library = 'ion',
      markerColor = getColor(data)
    )

    leaflet(crime2) %>%
      addTiles() %>%
      addAwesomeMarkers(~lon, ~lat, icon=icons)

  })
}

shinyApp(ui=ui, server=server)