使用gSimplify简化了带有空间多边形的writeOGR

12

我正在使用gSimplify（rgeos包）来简化shapefile的几何形状。该功能运行良好，但现在我无法在新的shapefile中写入输出。我尝试了一些方法：

writeOGR(simplyshape, file, driver="ESRI Shapefile", layer='test')

我懂了

obj必须是SpatialPointsDataFrame，SpatialLinesDataFrame或SpatialPolygonsDataFrame

与：

writePolyShape(simplyshape, file)

我得到：

错误：is（x，“ SpatialPolygonsDataFrame”）不是TRUE

shapefile r simplify rgdal

— 安德里亚兹
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8

将您的对象强制为适当的Spatial*DataFrame-class（点/线/多边形），例如，SpatialPolygons使用as(x, "SpatialPolygonsDataFrame" )：

R> l <- readWKT("LINESTRING(0 7,1 6,2 1,3 4,4 1,5 7,6 6,7 4,8 6,9 4)")
R> x1 <- gSimplify(p, tol=10)
R> class(x1)
[1] "SpatialPolygons"
attr(,"package")
[1] "sp"
R> x2 <- as(x, "SpatialPolygonsDataFrame")
R> class(x2)
[1] "SpatialPolygonsDataFrame"
attr(,"package")
[1] "sp"

— rcs
source

5

您需要将您的SpatialPolygons课程转换为SpatialPolygonsDataFrame课程。例如：

require(rgdal)
require(rgeos)

# Read shapefile
shp = 'C:/temp/myshp.shp'
myshp = readOGR(shp, layer = basename(strsplit(shp, "\\.")[[1]])[1])

# Read shapefile attributes
df = data.frame(myshp)

# Simplify geometry using rgeos
simplified = gSimplify(myshp, tol = 1000, topologyPreserve=FALSE)

# Create a spatial polygon data frame (includes shp attributes)
spdf = SpatialPolygonsDataFrame(simplified, df)

# Write to shapefile
writeOGR(spdf, layer = 'myshp_simplified', 'C:/temp', driver="ESRI Shapefile")

— 亚伦
source