带有传单的闪亮选择范围和数值变量(作为输入) [英] Shiny selecting ranges and numeric variable (as inputs) with leaflet

问题描述

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

On shiny, I would like to show a list of numerical variables and a slide bar so that a user could choose a numerical variable and a range. Then, observations below that number would show up as green, and observations between that range would be orange, and observations above that range would be red.

在我将它们放入闪亮的代码之前，下面的代码可以正常工作.但是我的闪亮代码无法正常工作，所有观察结果均为红色.

The codes below work fine before I put them into shiny. But my shiny codes don't work and all observations are red.

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)

这是无效的代码

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显示为红色的点"的问题吗?

Does anyone know how to fix 'all points showing up as red' problem?

先谢谢您！

推荐答案

一些更改:

1. 创建 selectInput 时，选择(和选择的)选项必须小写以匹配Crime2中的列名.

1. When you create the selectInput the choices (and selected) need to be lowercase to match the column names in crime2.

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

在您的 getColor 函数内部，您希望循环数据中的值，而不是输入$ var，因此您应该调用 var 而不是在lambda函数中输入$ var .

Inside of your getColor function you want to loop over the values in data, not input$var, so you should call var rather than input$var inside the lambda function.

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

当您实际创建图标时，您希望基于 data 中的值而不是整个Crime2数据集中的值来创建图标.

When you actually go to create your icons, you want them to be created based on the values in data, not the values in the entire crime2 dataset.

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

将它们放在一起:

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)

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