更改地图类型

Question

我有代码在地图上显示点如下：

m <- leaflet(mdt) %>% 
    addTiles('http://{s}.basemaps.cartocdn.com/dark_all/{z}/{x}/{y}.png', attribution='Map tiles by <a href="http://stamen.com">Stamen Design</a>, <a href="http://creativecommons.org/licenses/by/3.0">CC BY 3.0</a> &mdash; Map data &copy; <a href="http://www.openstreetmap.org copyright">OpenStreetMap</a>') m %>% 
    addCircles(~mdt$Pickup_longitude, ~mdt$Pickup_latitude, popup=mdt$Trip_type, weight = 3, radius=40,                   color="#ffa500", stroke = TRUE, fillOpacity = 0.8) %>% 
    addCircles(~mdt$Dropoff_longitude, ~mdt$Dropoff_latitude, popup=mdt$Trip_type, weight = 3, radius=40,                    color="#9dea3f", stroke = TRUE, fillOpacity = 0.8  ) %>% 
    addLegend("bottomright", colors= "#ffa500", labels="NYC'", title="Pickup & Drop off Locations")

我的地图外观如下：

如何更改地图类型，我想使用明确颜色的开放街道地图，如下所示：

我想只更改地图类型。什么是最简单的方法。

Answer 1

对于那些可能出现同样问题的人来说，这是答案。

m <- leaflet(mdt) %>% addTiles(options = providerTileOptions(opacity = .5)) m %>% addCircles(~mdt$Pickup_longitude, ~mdt$Pickup_latitude, popup=mdt$Trip_type, weight = 3, radius=40, color="#8B008B", stroke = TRUE, fillOpacity = 0.8) %>% addCircles(~mdt$Dropoff_longitude, ~mdt$Dropoff_latitude, popup=mdt$Trip_type, weight = 3, radius=40, 
               color="#00FF00", stroke = TRUE, fillOpacity = 0.8  )