动态地理信息可视化——leaflet构造路径图
根据先前几篇内容的框架，今天介绍leaflet在线地图的第三篇，以线条元素构造的路径图。
library(leaflet)
library(dplyr)
data<-read.table("D:/R/File/subwayline.txt",header=TRUE,stringsAsFactors = FALSE)
data$Type<-as.factor(data$Type)
data1<-filter(data,Type=="NO1")
data2<-filter(data,Type=="NO5")
以上我用百度地图的坐标拾取平台采点拾取的背景地铁一号线和五号线的车站地理位置信息，（因为没有现成的数据，只能手工采点，可能不是很准确）
今天要介绍的leaflet类型是线条，也即addPolylines函数，其基本语法如下：
addPolylines(map, lng = NULL,lat = NULL, #指定数据源并做经纬度声明
layerId = NULL,
group = NULL, #图层分组（制作动态可见性交互时使用）
stroke = TRUE, #是否呈现路径线
color = "#03F",weight = 5,opacity = 0.5, #关于线条的颜色、宽度、透明度
fill = FALSE, fillColor = color, fillOpacity = 0.2,
dashArray = NULL, smoothFactor = 1, noClip = FALSE, #线型参数，平滑度等
popup = NULL, options = pathOptions(), data = getMapData(map)) #弹窗、选项控制
以下构造色盘：
pal <- colorFactor(topo.colors(2),data$Type)
作图函数：使用默认点标识
leaflet()%>%
addTiles()%>%
addPolylines(data=data1,~lon,~lat,color="blue")%>%
addPolylines(data=data2,~lon,~lat,color="green")%>%
addMarkers(data=data,~lon, ~lat,popup = ~address)
使用可自定义的圆点标识车站位置
leaflet()%>%
addTiles()%>%
addPolylines(data=data1,~lon,~lat,color="blue")%>%
addPolylines(data=data2,~lon,~lat,color="green")%>%
addCircles(data=data,~lon, ~lat,popup = ~address,color="red")
leaflet()%>%
addTiles()%>%
addPolylines(data=data1,~lon,~lat,color="blue")%>%
addPolylines(data=data2,~lon,~lat,color="green")%>%
addCircleMarkers(data=data,~lon, ~lat,popup = ~address,color=~Type)
以下是几种比较常用的地图背景素材
addProviderTiles("Esri.WorldStreetMap")
addProviderTiles("Esri.WorldImagery")
addProviderTiles("Esri.WorldTerrain")
addProviderTiles("Esri.NatGeoWorldMap")
leaflet()%>%
addProviderTiles("Esri.WorldStreetMap")%>%
addPolylines(data=data1,~lon,~lat,color="blue")%>%
addPolylines(data=data2,~lon,~lat,color="green")%>%
addCircles(data=data,~lon, ~lat,popup = ~address,color=~Type)
leaflet()%>%
addProviderTiles("Esri.WorldImagery")%>%
addPolylines(data=data1,~lon,~lat,color="blue")%>%
addPolylines(data=data2,~lon,~lat,color="green")%>%
addCircles(data=data,~lon, ~lat,popup = ~address,color=~Type)
leaflet()%>%
addProviderTiles("Esri.WorldGrayCanvas") %>%
addPolylines(data=data1,~lon,~lat,color="blue")%>%
addPolylines(data=data2,~lon,~lat,color="green")%>%
addCircles(data=data,~lon, ~lat,popup = ~address,color=~Type)
leaflet()%>%
addProviderTiles("Esri.NatGeoWorldMap") %>%
addPolylines(data=data1,~lon,~lat,color="blue")%>%
addPolylines(data=data2,~lon,~lat,color="green")%>%
addCircles(data=data,~lon, ~lat,popup = ~address,color=~Type)
是不是觉得花样不够多呀，那好吧，以下这些，全部都送给你，那好不谢！
###############################
# OpenStreetMap.Mapnik
# OpenStreetMap.BlackAndWhite
# OpenStreetMap.DE
# OpenStreetMap.France
# OpenStreetMap.HOT
# OpenTopoMap
# Thunderforest.OpenCycleMap
# Thunderforest.Transport
# Thunderforest.TransportDark
# Thunderforest.SpinalMap
# Thunderforest.Landscape
# Thunderforest.Outdoors
# Thunderforest.Pioneer
# OpenMapSurfer.Roads
# OpenMapSurfer.Grayscale
# Hydda.Full
# Stamen.Toner
# Stamen.TonerBackground
# Stamen.TonerLite
# Stamen.Watercolor
# Stamen.Terrain
# Stamen.TerrainBackground
# Stamen.TopOSMRelief
# Esri.WorldStreetMap
# Esri.DeLorme
# Esri.WorldTopoMap
# Esri.WorldImagery
# Esri.WorldTerrain
# Esri.WorldShadedRelief
# Esri.WorldPhysical
# Esri.OceanBasemap
# Esri.NatGeoWorldMap
# Esri.WorldGrayCanvas
# MtbMap
# CartoDB.Positron
# CartoDB.PositronNoLabels
# CartoDB.PositronOnlyLabels
# CartoDB.DarkMatter
# CartoDB.DarkMatterNoLabels
# CartoDB.DarkMatterOnlyLabels
# HikeBike.HikeBike
# HikeBike.HillShading
# NASAGIBS.ModisTerraTrueColorCR
# NASAGIBS.ModisTerraBands367CR
# NASAGIBS.ViirsEarthAtNight2012
# NASAGIBS.ModisTerraLSTDay
# NASAGIBS.ModisTerraSnowCover
# NASAGIBS.ModisTerraAOD
# NASAGIBS.ModisTerraChlorophyll
#################################################
细数也有好几十个，够你玩一阵子了，使用方法仅仅是通过设置图层函数进行调用，然后就可以愉快的在图层上面进行可视化操作了。
addProviderTiles("地图类型")
我是分割线〜
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