R 中的 shapefile：按相似属性聚合几何

Question

我有一个 SpatialPolygonsDataFrame (myshape) 格式的 shapefile，其中有几个子分区由同一区域的 A、B、C 等表示，例如。 LIMOEIRO064A、LIMOEIRO064B等适用于几个不同的领域。例如，我想合并 LIMOEIRO064 的几何图形。为此，我尝试：

# Packages
library(raster)
library(rgdal)

# Download and unzip the shapefile example
download.file('https://www.dropbox.com/s/2zoproayzqvj1cc/myshape.zip?dl=0',
              destfile="myshape.zip",
              method="auto") 
unzip(paste0(getwd(),"/myshape.zip"))

#Read target shapefile -----------------------------------------------
myshape <- readOGR (".","myshape") 
proj4string(myshape) <- CRS("+proj=longlat +ellps=GRS80 +no_defs")

# Create unique ID for each area without sub-units A, B, C, etc. if have in CD_TALHAO attribute
str(myshape@data)
#'data.frame':  419 obs. of  7 variables:
# $ OBJECTID  : chr  "563774" "563783" "795091" "795092" ...
# $ ID_PROJETO: chr  "131" "131" "131" "131" ...
# $ PROJETO   : chr  "LIMOEIRO" "LIMOEIRO" "LIMOEIRO" "LIMOEIRO" ...
# $ CD_TALHAO : chr  "064A" "017B" "V00204" "V00702" ...
# $ SHAPE_AREA: num  1.07e-05 1.67e-05 1.72e-07 2.46e-07 2.07e-06 ...
# $ SHAPE_LEN : num  0.02774 0.01921 0.00401 0.005 0.01916 ...
# $ CODE      : chr  "LIMOEIRO064A" "LIMOEIRO017B" "LIMOEIROV00204" "LIMOEIROV00702" ...
myshape@data$UNIQUE<-gsub("[a-zA-Z]", "", myshape@data$CD_TALHAO)

# New unique CODE
myshape@data$CODE<-paste0(myshape@data$PROJETO,myshape@data$UNIQUE)
#unique(myshape@data$CODE)
#  [1] "LIMOEIRO064"     "LIMOEIRO017"     "LIMOEIRO00204"   "LIMOEIRO00702"   "LIMOEIRO06501"   "LIMOEIRO02403"  
#  [7] "LIMOEIRO00201"   "LIMOEIRO05002"   "LIMOEIRO03516"   "LIMOEIRO02203"   "LIMOEIRO02904"   "LIMOEIRO00405"  
# [13] "LIMOEIRO01804"   "LIMOEIRO01608"   "LIMOEIRO03106"   "LIMOEIRO00101"   "LIMOEIRO010"     "LIMOEIRO035"    
# [19] "LIMOEIRO020"     "LIMOEIRO001"     "LIMOEIRO056"     "LIMOEIRO059"     "LIMOEIRO06402"   "LIMOEIRO01801"
#...
# [295] "LIMOEIRO011"     "LIMOEIRO06408"

现在，我想在 new_myshape 中合并具有相同代码标识的 shapefile 和几何图形，但我发现 bind() 和 union() 等选项对我不起作用。我需要通过 myshape@data$CODE 聚合之类的东西或类似这样的选项。请问有什么想法吗？

Answer 1

以下是使用 terra

的方法

library(terra)
f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
va <- aggregate(v, "ID_1")

您可以使用与 raster/sp

相同的方法

p <- shapefile(system.file("external/lux.shp", package="raster"))
pa <- aggregate(p, "ID_1")

R 中的 shapefile：按相似属性聚合几何

shapefile in R: aggregate geometries by similar attributes

r

raster

shapefile

r-raster