raster::erase 函数 - RGEOSBinTopoFunc 中的错误：TopologyException

Question

我按照我之前的 post 解决方案使用栅格包擦除功能来剪切和溶解重叠多边形 -

对于一些多边形，我在使用擦除功能时遇到以下错误：

RGEOSBinTopoFunc (spgeom1, spgeom2, byid, id, drop_lower_td, unaryUnion_if_byid_false, 错误: TopologyException：输入geom 1无效：在1.1197332302192855 47.203098020153668 at 1.1197332302192855 47.203098020153668

处或附近自交

library(raster)
library(rgeos)
library(sp)

fields <- gBuffer(fields, byid=TRUE, width=0) # Expands the given geometry to include 
the area within the specified width 

zone <- fields[fields$Type == "Zone", ]
plot <- fields[fields$Type == "Plot", ]

d <- erase(zone, plot) #issue here
spplot(d, "Rx")

# I tried using rgeos::gBuffer to avoid RGEOSBinTopology Exception but it did not worked out. Any guidance in this area would be really helpful.

zone <- gBuffer(zone, byid=TRUE, width=0)
plot <- gBuffer(plot, byid=TRUE, width=0)

Answer 1

剧情多边形真的很乱。即使它们是有效的。问题出现在 erase 成为聚合 ("dissolves") 参数 y ("fields") 但生成无效拓扑。我需要研究如何最好地抓住它，但是，现在（也许还有一段时间），这里有一个使用 cleangeo 的解决方法，但您可能想要使用一个工具来清理字段多边形（捕捉顶点）- -- 也许使用 Rmapshaper？

library(raster)
library(rgeos)

f <- "WUERZ-I-WW _ Plot _TrialMap.shp"
fields = shapefile(f)
zone <- fields[fields$Type == "Zone", ]
plot <- fields[fields$Type == "Plot", ]

aplot <- aggregate(plot)
rgeos::gIsValid(aplot)
#[1] FALSE
#Warning message:
#In RGEOSUnaryPredFunc(spgeom, byid, "rgeos_isvalid") :
#  Self-intersection at or near point 13.033265979999999 51.190776640000003

library(cleangeo)
cplot <- clgeo_Clean(aplot)
rgeos::gIsValid(cplot)
# TRUE

d <- erase(zone, cplot)

raster::erase 函数 - RGEOSBinTopoFunc 中的错误：TopologyException

raster::erase function - Error in RGEOSBinTopoFunc : TopologyException

r

raster

r-raster

rgeo-shapefile