R传单中有没有办法为某些位置分配不同的图标？

Question

我正在为当地学区开发一款闪亮的应用程序，该应用程序将为根据空气污染状况不应放假的学校显示一面旗帜。该应用程序将针对特定的一天进行过滤，我添加了一个名为 recess 的列，根据空气污染物，该列被标记为“Stay Inside！”或“继续播放！”。然后我创建了一个图标列表 - 一个 child 播放图标“继续播放！”以及“呆在里面！”的危险图标。

我遇到问题的地方是函数。我试图让它告诉传单为当天可以放假的学校显示 child 播放图标，为当天不应该放假的学校显示危险图标。

这是我遇到的问题的一个例子：

# Load Libraries
library(tidyverse)
library(leaflet)



# Vectors
Schools <- c("CHS", "BHS", "DHS")
latitude <- c(60, 61, 62)
longitude <- c(100, 101, 102)
recess <- c("Stay Inside!", "Play on!", "Play on!")

# Data frame
bad_air <- data.frame(Schools, latitude, longitude, recess)

# Map Icons
recessIcons <- awesomeIconList(
  child = makeAwesomeIcon(icon = "child", library = "fa", 
                          markerColor = "blue"),
  danger = makeAwesomeIcon(icon = "exclamation", library = "fa", 
                           markerColor = "darkred")
)

# Function to grab map icon
getrecessIcon <- function(bad_air){
  sapply(bad_air$recess, function(recess){
    if(bad_air$recess == "Stay Inside"){
      recessIcons$child
    } else {
      recessIcons$danger
    }
  })
}

# Build Leaflet Map
leaflet(bad_air) %>%
  addProviderTiles(providers$CartoDB.Positron) %>% 
  addAwesomeMarkers(~longitude,
                    ~latitude,
                    icon = ~getrecessIcon(bad_air),
                    label = ~Schools,
                    labelOptions = labelOptions(noHide = F))

然后我得到这个错误：

Warning messages:
1: In if (bad_air$recess == "Stay Inside") { :
  the condition has length > 1 and only the first element will be used
2: In if (bad_air$recess == "Stay Inside") { :
  the condition has length > 1 and only the first element will be used
3: In if (bad_air$recess == "Stay Inside") { :
  the condition has length > 1 and only the first element will be used

我哪里错了？任何帮助将不胜感激！

Answer 1

我认为这可以在不使用函数的情况下进行简化。

添加一列 icon 以指明您要为每个 school/row 使用哪个图标：

bad_air$icon <- ifelse(bad_air$recess == "Stay Inside!", "danger", "child")

然后，通过从您创建的 recessIcons 中选择适当的图标（即 recessIcons[icon]）来访问每所学校所需的图标：

# Build Leaflet Map
leaflet(bad_air) %>%
  addProviderTiles(providers$CartoDB.Positron) %>% 
  addAwesomeMarkers(~longitude,
                    ~latitude,
                    icon = ~recessIcons[icon],
                    label = ~Schools,
                    labelOptions = labelOptions(noHide = F))

R传单中有没有办法为某些位置分配不同的图标？

Is there a way in R leaflet to assign different icons to certain locations?

r

function

leaflet

reprex