传单R中的自定义标记传说

Question

我有一个R Shiny应用程序，它使用Leaflet创建交互式地图。在此地图上，分类变量用于指定不同类型的点，并使用自定义标记（不同的图标，根据因子级别）进行可视化。

我想要做的是添加一个图例的情节，但有图例显示各种标记图标，而不是纯色。 legends tutorial不包括此。

我遇到了另一个SO answer that seems to solve this - 但它是在JavaScript中完成的，我不确定如何翻译它/是否可以翻译成在R中工作。任何人都知道如何完成此任务？

一个基本的可重复的例子：

library(leaflet) 

# Sample Data 
data(quakes) 
quakes <- quakes[1:10,] 

# Choose Icon: 
leafIcons <- icons(
    iconUrl = ifelse(quakes$mag < 4.6, 
        "http://leafletjs.com/docs/images/leaf-green.png", 
        "http://leafletjs.com/docs/images/leaf-red.png" 
), 
    iconWidth = 38, iconHeight = 95, 
    iconAnchorX = 22, iconAnchorY = 94) 

# Produce Map: 
leaflet(data = quakes) %>% addTiles() %>% 
    addMarkers(~long, ~lat, icon = leafIcons) 

Answer 1

虽然使用的图标是addLegend（）not currently implemented，艺辉建议使用的AddControl（），采用原始的HTML - 这完美的作品！

library(leaflet) 

# Sample Data 
data(quakes) 
quakes <- quakes[1:10,] 

# Choose Icon: 
leafIcons <- icons(
    iconUrl = ifelse(quakes$mag < 4.6, 
        "http://leafletjs.com/docs/images/leaf-green.png", 
        "http://leafletjs.com/docs/images/leaf-red.png" 
), 
    iconWidth = 38, iconHeight = 95, 
    iconAnchorX = 22, iconAnchorY = 94) 

html_legend <- "<img src='http://leafletjs.com/docs/images/leaf-green.png'>green<br/> 
<img src='http://leafletjs.com/docs/images/leaf-red.png'>red" 

# Produce Map: 
leaflet(data = quakes) %>% addTiles() %>% 
    addMarkers(~long, ~lat, icon = leafIcons) %>% 
    addControl(html = html_legend, position = "bottomleft") 

主要生产：

Answer 2

响应上面的注释：你可以改变的传奇图标的大小，无论你定义的初始大小。您所要做的就是将

style='width:(desired_width)px;height:(desired_height)px'; 添加到HTML部分。

具体来说，您的代码想：

library(leaflet) 

# Sample Data 
data(quakes) 
quakes <- quakes[1:10,] 

# Choose Icon: 
leafIcons <- icons(
iconUrl = ifelse(quakes$mag < 4.6, 
       "http://leafletjs.com/docs/images/leaf-green.png", 
       "http://leafletjs.com/docs/images/leaf-red.png" 
), 
    iconWidth = 38, iconHeight = 95, 
    iconAnchorX = 22, iconAnchorY = 94) 

html_legend <- "<img src='http://leafletjs.com/docs/images/leaf-green.png' 
style='width:10px;height:10px;'>green<br/> 

<img src='http://leafletjs.com/docs/images/leaf-red.png' 
style='width:10px;height:10px;'>red" 

# Produce Map: 
leaflet(data = quakes) %>% addTiles() %>% 
addMarkers(~long, ~lat, icon = leafIcons) %>% 
addControl(html = html_legend, position = "bottomleft")