[R-sig-Geo] Unable to apply 'gIntersection' successfully

[satishr]

Hi, I am trying to calculate fraction of a polygon that is intersected by
another polygon. I have data in two shape files; the first file corresponds
to a rectangular grid with uniform intervals whereas the second file
corresponds to US climate divisions, which are polygons. The script worked
fine expect for one ploygon; please see the below message. It looks like
coordinates of a polygon are corrupted but I am not sure whether it is the
cause and if so how to fix it. Any feedback is greatly appreciated. Data
sets and excerpts of my script are below mentioned.
Thanks,
Satish


library(rgdal); library(rgeos)

grid=readOGR("C:/Temp","Gaussian_Poylgon_ExtendedCONUS")

climagdiv=readOGR("C:/Temp","US102ClimateDivisions")

iclimdiv=45

print(paste("Climate Division ",iclimdiv,sep=""))

int = gIntersects(climagdiv[iclimdiv,],grid,byid=TRUE)

vec = vector(mode="list", length=dim(int)[2]) 

for (i in seq(along=vec)) vec[[i]] =
try(gIntersection(climagdiv[iclimdiv,],grid[int[,i],], byid=TRUE))

Error in RGEOSBinTopoFunc(spgeom1, spgeom2, byid, id, "rgeos_intersection")
: 
  TopologyException: found non-noded intersection between LINESTRING
(-91.043 32.5763, -90.964 32.5763) and LINESTRING (-90.964 32.5763, -91.035
32.5763) at -90.964 32.5763

Data sets:

1. Rectangular Grid 

http://r-sig-geo.2731867.n2.nabble.com/file/n7240529/GaussianPolygonExtendedCONUS.zip
GaussianPolygonExtendedCONUS.zip 

2. US 102 climate divisions 

http://r-sig-geo.2731867.n2.nabble.com/file/n7240529/US102ClimateDivisions.zip
US102ClimateDivisions.zip 


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