R语言 – 绘制美国地图
在R中画地图先从简单的maps包开始。 library(“maps”) 在这个maps包中有一些数据集，用命令data(package=”maps”)，可以看到如下数据： canada.cities Database of Canadian cities county.fips FIPS county codes for US County Map countyMapEnv United States County Map franceMapEnv France Map italyMapEnv Italy Map nzMapEnv New Zealand Basic Map ozone Sample datasets state.carto.center United States State Population Cartogram Map state.cartoMapEnv United States State Population Cartogram Map state.fips FIPS state codes for US 48 State Map state.vbm.center United States State Visibility Base Map state.vbmMapEnv United States State Visibility Base Map stateMapEnv United States State Boundaries Map unemp Sample datasets us.cities Database of US cities usaMapEnv United States Coast Map votes.repub Sample datasets world.cities Database of world cities world2MapEnv Pacific Centric Low resolution World Map worldMapEnv Low resolution World Map
