ggplot2（R）中的多边形着色

Question

我对 R 很陌生。我设法用下面的代码制作了下面的地图。

我想将地图上最右边的多边形（在代码中表示为“WestTerr”）与其他三个多边形（在代码中表示为“Serena”）不同的颜色。我已经尝试过各种各样的事情，这些事情都给我带来了错误。有谁知道如何帮助我？

library(ggmap)
library(RgoogleMaps)
library(foreign)
library(raster)
library(sp)
library(rgeos)
library(spatstat)
library(maptools)
library(rgdal)
library(ggplot2)

CenterOfMap <- geocode("-1.4, 35.08")

MasaiMara <- get_map(c(lon=CenterOfMap$lon, lat=CenterOfMap$lat), zoom = 10, 
                     maptype = "roadmap", source = "google")

MasaiMaraMap <- ggmap(MasaiMara)

setwd("Territories_Jenna/")

SouthTerr <- readOGR(".","SouthMCP")
SouthTerr <- spTransform(SouthTerr, CRS("+proj=longlat +datum=WGS84"))
fortify(SouthTerr)

HZTerr <- readOGR(".","HZMCP")
HZTerr <- spTransform(HZTerr, CRS("+proj=longlat +datum=WGS84"))
fortify(HZTerr)

SandHZ <- gUnion(SouthTerr, HZTerr)
SandHZ <- spTransform(SandHZ, CRS("proj=longlat +datum=WGS84"))
fortify(SandHZ)

MapwithSandHZ <- MasaiMaraMap +
                 geom_polygon(aes(x=long, y=lat, group=group),
                              fill = "black", size=.7, color="black",
                              data=SandHZ, alpha=0)

NorthTerr <- readOGR(".","NorthMCP")
NorthTerr <- spTransform(NorthTerr, CRS("+proj=longlat +datum=WGS84"))
fortify(NorthTerr)

MapwithNorth <- MasaiMaraMap +
                geom_polygon(aes(x=long, y=lat, group=group),
                             fill = "black", size=.7, color="black",
                             data=NorthTerr, alpha=0)

Serena <- gUnion(SandHZ, NorthTerr)
Serena <- spTransform(Serena, CRS("proj=longlat +datum=WGS84"))
fortify(Serena)

MapwithSerena <- MasaiMaraMap +
                 geom_polygon(aes(x=long, y=lat, group=group),
                              fill = "black", size=.7, color="black",
                              data=Serena, alpha=0)

WestTerr <- readOGR(".","WestMCP")
WestTerr <- spTransform(WestTerr, CRS("+proj=longlat +datum=WGS84"))
fortify(WestTerr)

MapwithWest <- MasaiMaraMap +
               geom_polygon(aes(x=long, y=lat, group=group), 
                            fill = "red", size=.7, color="red",
                            data=WestTerr, alpha=0)

AllTerrs <- gUnion(Serena, WestTerr)
AllTerrs <- spTransform(AllTerrs, CRS("proj=longlat +datum=WGS84"))
fortify(AllTerrs)

MapwithAllTerrs <- MasaiMaraMap +
                   geom_polygon(aes(x=long, y=lat, group=group),
                                fill = "red", size=.7, color="red",
                                data=AllTerrs, alpha=0)

MapwithAllTerrs

Answer 1

我无权访问您的数据，因此我创建了一个示例数据。看到您的代码，您在四个调用中创建了四个多边形。我认为您想组合所有数据并绘制多边形。当您使用 fortify() 时，您会看到一个 id 列。如果您合并数据，您希望确保每个多边形都有一个唯一的 ID。我认为，一旦有了数据，您就可以直接完成工作。您可以使用scale_fill_manual()手动更改多边形的颜色

library(ggmap)
CenterOfMap <- geocode("-1.4, 35.08")

MasaiMara <- get_map(c(lon=CenterOfMap$lon, lat=CenterOfMap$lat), zoom = 10, 
                     maptype = "roadmap", source = "google")
                 
ggmap(MasaiMara) +
geom_polygon(data = mydf, aes(x = long, y = lat, group = id, fill = factor(id))) +
scale_fill_manual(values = c("red", "red", "blue"))

数据

mydf <-structure(list(id = c(1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 
3L, 3L, 3L, 3L, 3L), long = c(34.97, 34.95, 34.95, 34.97, 34.97, 
35, 34.82, 34.83, 35, 35, 35.2, 35.1, 35.1, 35.2, 35.2), lat = c(-1.38, 
-1.38, -1.4, -1.4, -1.38, -1.6, -1.6, -1.7, -1.7, -1.6, -1.43, 
-1.43, -1.5, -1.5, -1.43)), class = c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -15L), .Names = c("id", "long", "lat"), spec = structure(list(
cols = structure(list(id = structure(list(), class = c("collector_integer", 
"collector")), long = structure(list(), class = c("collector_double", 
"collector")), lat = structure(list(), class = c("collector_double", 
"collector"))), .Names = c("id", "long", "lat")), default = structure(list(), class = c("collector_guess", 
"collector"))), .Names = c("cols", "default"), class = "col_spec"))