用图案填充地理空间多边形 - R.

Question

我有一张波斯尼亚地图，其中的市镇根据居住在那里的少数民族而着色。 但是，我想使用不同的图案而不是颜色（或灰度），因为它将以黑白打印。
我搜索过，但找不到办法。有没有人知道如何做到这一点？ Link to shapefile

到目前为止，这是我的代码：

library(RColorBrewer)
library(maptools)
library(rgdal)
library(rgeos)
library(ggplot2)
library(gridExtra)

setwd("path")

bosnia <- readOGR("path/to/file", "bosnia_analysis", 
                verbose = TRUE, stringsAsFactors = FALSE)

bosnia <- readShapePoly("path/to/bosnia_analysis.shp",proj4string=CRS("+proj=longlat +datum=WGS84"))
bosnia.df <- bosnia@data

serbs <- bosnia[bosnia$SEPRIORITY > bosnia$CRPRIORITY & bosnia$SEPRIORITY > bosnia$MOPRIORITY,]
croats <-  bosnia[bosnia$CRPRIORITY > bosnia$SEPRIORITY & bosnia$CRPRIORITY > bosnia$MOPRIORITY,]
moslems <- bosnia[bosnia$MOPRIORITY > bosnia$CRPRIORITY & bosnia$MOPRIORITY > bosnia$SEPRIORITY,]

p <- ggplot(bosnia, aes(x = long, y = lat, group = group)) + 
  geom_polygon(aes(x=long,y=lat,group=group), fill="white", colour="grey") +
  geom_polygon(data=serbs, aes(x=long,y=lat,group=group), fill="black", colour="grey") +
  geom_polygon(data=croats, aes(x=long,y=lat,group=group), fill="green", colour="grey") +
  geom_polygon(data=moslems, aes(x=long,y=lat,group=group), fill="red", colour="grey") +
  # Styling
  coord_map() +
  labs(x="Bosnia", y=" ") + 
  theme_bw() + 
  theme(panel.grid.minor=element_blank(), panel.grid.major=element_blank()) + 
  theme(axis.ticks = element_blank(), axis.text.x = element_blank(), axis.text.y = element_blank()) + 
  theme(panel.border = element_blank())

p

这给了我以下地图：

Answer 1

为基本图形抛弃ggplot。虽然只有三组我会认为黑色，白色和中灰色可以正常工作。

require(sp)
require(rgdal)

bosnia = readOGR(".","bosnia_analysis")
proj4string(bosnia)=CRS("+init=epsg:4326")

不是分成3个数据集，而是从三个TRUE / FALSES中创建一个新的分类变量：

serbs = bosnia$SEPRIORITY > bosnia$CRPRIORITY & bosnia$SEPRIORITY > bosnia$MOPRIORITY
croats =  bosnia$CRPRIORITY > bosnia$SEPRIORITY & bosnia$CRPRIORITY > bosnia$MOPRIORITY
moslems = bosnia$MOPRIORITY > bosnia$CRPRIORITY & bosnia$MOPRIORITY > bosnia$SEPRIORITY

bosnia$group=NA
bosnia$group[serbs]="Serb"
bosnia$group[croats]="Croat"
bosnia$group[moslems]="Moslem"
bosnia$group=factor(bosnia$group)

检查无人在多个类别中：

sum(serbs&&croats&&moslems) # should be zero

现在你可以获得一个非常有色的情节：

spplot(bosnia, "group")

但我不知道如何在不同的单声道风格中做到这一点，所以它回到基本图形：

plot(bosnia,density=c(5,10,15)[bosnia$group], angle=c(0,45,90)[bosnia$group])

根据品味调整参数。你可以使用legend用相同的参数做一个很好的图例。

Answer 2

有点晚了，但这可能会有所帮助。您可以使用sf创建网格并对其进行处理以提取特定点并将其连接以创建新的图案：

library(sf)

bosnia <- st_read("~/R/mapslib/OTROS/Bosnia")
st_crs(bosnia) <- 4326
serbs <-
  bosnia[bosnia$SEPRIORITY > bosnia$CRPRIORITY &
           bosnia$SEPRIORITY > bosnia$MOPRIORITY, ]
croats <-
  bosnia[bosnia$CRPRIORITY > bosnia$SEPRIORITY &
           bosnia$CRPRIORITY > bosnia$MOPRIORITY, ]
moslems <-
  bosnia[bosnia$MOPRIORITY > bosnia$CRPRIORITY &
           bosnia$MOPRIORITY > bosnia$SEPRIORITY, ]

ex = list(
  horizontal = c(1, 2),
  vertical = c(1, 4),
  left2right = c(2, 4),
  right2left = c(1, 3)
)
pattern <- function(x, size, pattern) {
  ex = list(
    horizontal = c(1, 2),
    vertical = c(1, 4),
    left2right = c(2, 4),
    right2left = c(1, 3)
  )
  fillgrid = st_make_grid(x, cellsize = size)
  endsf = lapply(1:length(fillgrid), function(j)
    sf::st_linestring(sf::st_coordinates(fillgrid[j])[ex[[pattern]], 1:2]))
  endsf = sf::st_sfc(endsf, crs = sf::st_crs(x))
  endsf = sf::st_intersection(endsf, x)
  endsf = endsf[sf::st_geometry_type(endsf)
                %in% c("LINESTRING", "MULTILINESTRING")]
  endsf = sf::st_line_merge(sf::st_union(endsf))
  return(endsf)
}

serbgrid = pattern(serbs, 0.05, "vertical")
moslgrid = pattern(moslems, 0.05, "left2right")
crogrid = pattern(croats, 0.05, "horizontal")


par(mar = c(0, 0, 0, 0))
plot(st_geometry(bosnia))
plot(serbgrid, add = T)
plot(moslgrid, add = T)
plot(crogrid, add = T)

请注意，这是我开发的功能的简化版本，您可以在here上看到完整的代码this post和完整的演示。