将阴影图层添加到R中的地图

我正在为区域内的各个学校创建地图，并且想要在学校边界周围创建阴影区域。我可以使用QGIS手动完成，但是希望能够在R中生成类似的东西。我现在可以在地图上绘制一些人口统计变量，添加学校位置和边界。有一个循环会自动为每所学校创建一张新地图，并将其插入到knitr报告中。将阴影图层添加到R中的地图

我无法弄清楚的是如何创建一个图层来遮蔽边界以外的区域。这是我的地图使用R：

但是想使它看起来更像是这样的：但是它是基于内核

我试着从GISTools的add.masking功能点的密度，而不是多边形。

我的代码看起来像这样（的道歉不被重现的，因为他们是形状文件坐在一个安全的驱动器上。

# Load Shape files 
proj<- CRS("+init=epsg:32617") 

schoolBound <- readShapePoly("J:/GIS/Data/Catchments/ElementaryAreas.shp", proj4string= proj) 
schools <- readShapePoints("J:/GIS/Data/Schools/ElementarySchools.shp", proj4string= proj) 
roads <- readShapePoints("J:/GIS/Data/Roads/MajorRoads.shp") 
da <- readShapePoly("J:/GIS/Data/Dissemination Areas 2011/da2011.shp", 
         proj4string = proj) 

SCH <- "School A" 

# Subset shape files for area around school 

school1Bound <- schoolBoundR [schoolBoundR$SchoolName == paste(SCH),] 
school1BoundBuff <- gBuffer(school1Bound, width = 15) # Adds buffer around geometry 
school1Point <- schoolsR [schoolsR$Name == paste(SCH),] 
roadsBound <- roadsR[apply(gIntersects(roadsR, school1BoundBuff, byid = TRUE),2,any),] 

# Plot map and add layers 

plot(school1BoundBuff) 
plot(da, 
    add = TRUE, 
    col=colours[findInterval(da$sri, brks,all.inside=TRUE)], # Adds colour palette to Social Risk Index 
    axes=F) 
plot(school1Point, add = TRUE, pch = 15, col = "blue") 
plot(roadsBound, add = TRUE, col = "gray60") 
plot(school1Bound, add = TRUE, lwd = 5)

来源

2015-08-28 Greg

这将是困难的，你这个节目没有你的shape文件，但尝试http://stackoverflow.com/questions/29624895/how-to-add-a-hole-跟着一起在空间多边形数据框中为空间切出一个洞然后使用'gUnaryUnion'这样的东西来分解被遮挡的多边形。 – hrbrmstr

我已经从这个添加颜色代码到数据文件想出一个办法问题：R - stuck with plot() - Colouring shapefile polygons based upon a slot value

[email protected]$filter <- NA 
[email protected]@data$filter[[email protected]$Code == SCH] <- 1 
[email protected]@data$filter[[email protected]$Code != SCH] <- 0 

[email protected]$COLOUR <- "#FFFFFF" 
[email protected]@data$COLOUR[(as.numeric(as.character([email protected]$filter)) %% 10) == 0] <- "white" 
[email protected]@data$COLOUR[(as.numeric(as.character([email protected]$filter)) %% 10) == 1] <- NA 

## Add layers to plot 
plot(school1BoundBuff) 
plot(da, 
    add = TRUE, 
    col=colours[findInterval(da$sri, brks,all.inside=TRUE)], # Adds colour palette to Social Risk Index 
    axes=F) 
plot(school1Point, add = TRUE, pch = 15, col = "blue") 
plot(roadsBound, add = TRUE, col = "gray60") 
plot(schoolBound, add = TRUE, col = [email protected]$COLOUR)

来源

2015-09-02 18:35:57 Greg

将阴影图层添加到R中的地图

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