leaflet for R(2)—— learletCN

王致远

2018/09/28

library(leaflet)
library(leafletCN)

10. LeafletCN

10.1 函数简介

  • regionNames：找地名函数，极其方便
  • demomap：有地名就给你输出一个交互、动态的区域图，真方便

  • geojsonMap：作用是分区块标色

  • amap ()：中国国情，高德地图的象征
  • read.geoShape：可以将geojson的对象,保存成spdataframe,以方便leaflet调用

  • leafletGeo：地图+小显示框，用地图名以及一个数据框创建一个sp的对象

regionNames

regionNames("河北")
##  [1] "承德市"   "张家口市" "保定市"   "唐山市"   "沧州市"   "石家庄市"
##  [7] "邢台市"   "邯郸市"   "秦皇岛市" "衡水市"   "廊坊市"
regionNames("承德市")
## Warning: JSON string contains (illegal) UTF8 byte-order-mark!
##  [1] "鹰手营子矿区"         "双桥区"               "围场满族蒙古族自治县"
##  [4] "承德县"               "丰宁满族自治县"       "宽城满族自治县"      
##  [7] "隆化县"               "滦平县"               "平泉县"              
## [10] "双滦区"               "兴隆县"

regionNames的粒度是省级、县级，在细分就没有了。执行regionNames()之后，可以知道包里面存着哪些地方，是否有你要的内容。

demomap

#install.packages("rgeos")
demomap("杭州")
## Warning: JSON string contains (illegal) UTF8 byte-order-mark!

geojsonMap 地图标色函数

dat = data.frame(name = regionNames("china"),
                 value = runif(34))
geojsonMap(dat,"china")
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Legend
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amap

高德地图

read.geoShape

if(require(sp)){
  filePath = system.file("geojson/china.json",package = "leafletCN")
  map = read.geoShape(filePath)
  plot(map)
}
## 载入需要的程辑包：sp

10.2 案例

案例一：单点标记

leaflet() %>%
  amap() %>%  
  addMarkers(lng=121.48, lat=31.22, popup="企业天地")

案例二：多点标注

#iconList 生成小框框
iconList = awesomeIconList(
  "home" = makeAwesomeIcon(icon = "home",markerColor = "skyblue"),
  "weixin" = makeAwesomeIcon(icon = "cutlery",markerColor = "red"),
  "bank" = makeAwesomeIcon(icon = "plus-sign",markerColor = "orange"),
  "automobile" = makeAwesomeIcon(icon = "trash",markerColor = "purple"),
  "coffee" = makeAwesomeIcon(icon = "book")
)
#每个小框框的坐标，经纬度
geo = data.frame(lon = rep(121.44, 5),
                 lat = rep(31.22, 5),
                 city = rep("Shanghai", 5))

#坐标进行微调，使得有差异
geo$lon = geo$lon+rnorm(5,0,0.003)
geo$lat = geo$lat+rnorm(5,0,0.003)

#小框框的属性
geo$type = c("home",
             "weixin",
             "bank" ,
             "automobile", 
             "coffee" )

#在高德地图上进行绘制
leaflet(geo) %>% amap() %>%
  addMiniMap() %>% 
  addAwesomeMarkers(icon = ~iconList[type])

案例三：分区域显示色彩

if(require(leaflet)){
  region=regionNames("浙江")
  dat = data.frame(region,runif(length(region)))

  map = leafletGeo("浙江", dat)

  #涂色环节
  pal <- colorNumeric(
    palette = "Blues",
    domain = map$value)

  #载入高德地图amap
  leaflet(map) %>% amap() %>%
  #加入框边界及颜色
    addPolygons(stroke = TRUE,
                smoothFactor = 1,
                fillOpacity = 0.7,
                weight = 1,
                color = ~pal(value),
                popup = ~htmltools::htmlEscape(popup)
    ) %>%
    #加入右下角边框
    addLegend("bottomright", pal = pal, values = ~value,
              title = "legendTitle",
              labFormat = leaflet::labelFormat(prefix = ""),
              opacity = 1)
}
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legendTitle
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案例四：地图+点集区域+复选框+NASA星空图

#数据生成
geo = data.frame(long = rep(121.44, 1000),
                 lat = rep(31.22, 1000),
                 mag=rep(5,1000))
#mag函数是用来衡量后面，点集范围大小

geo$long = geo$long+rnorm(1000,0,1)
geo$lat = geo$lat+rnorm(1000,0,1)
geo$mag = geo$mag+rnorm(1000,0,1)
outline <- geo[chull(geo$long, geo$lat),]


map <- leaflet(geo) %>%

  # 底层阶段
  # 第一层底图，高德
  amap(group = "高德") %>%                        
  # 第二层底图，黑底图NASA
  addProviderTiles(providers$NASAGIBS.ViirsEarthAtNight2012, group = "黑底") %>%   
  # 第三层底图，白底层
  addProviderTiles(providers$Stamen.TonerLite, group = "白底") %>% 


  # 点集+区域轮廓阶段
  addCircles(~long, ~lat, ~7^mag/50, stroke = F, group = "圈点",color="#97FFFF") %>%          
  # 描点画圈，stroke=T的话，边界包边，丑

  # 绘制轮廓，利用前面的凸集点
  addPolygons(data = outline, lng = ~long, lat = ~lat,
              fill = F, weight = 2, color = "#FFFFCC", group = "轮廓") %>% 

  # 复选框       
  addLayersControl( 
    baseGroups = c("高德", "黑底", "白底"),                     
    #显示层
    overlayGroups = c("圈点", "轮廓"),
    options = layersControlOptions(collapsed = FALSE)
  )
map
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