subset of spatial points
Johannes Radinger <JRadinger <at> gmx.at> writes:
Hello, I tried to subset a spatial points
dataframe with:
subset(df,Attr == i) but then I get the error: "Fehler in
subset.SpatialPointsDataFrame(df, Attr == i) :
Objekt 'Attr' nicht gefunden" so it the object 'Attr' couldn't be found.
There is definetly
a column called 'Attr' in the
spatialpointsdataframe. This is also
proofed when I transform my spatial
points into a ordinary dataframe before everything works (there is the
column 'Attr'): df <- as.data.frame(df) It gets strange now: when I tried to make a short sample
script... everything
works, so I don't know why the 'Attr'
couldn't be found in
my script although it exists...?? library(rgdal) X <- c(9.3182,9.31609,9.29932, 9.14613,
9.32783)
Y <- c(54.6461, 54.439, 54.4786,
54.6561, 54.5668)
Attr <- factor(c("A","A","B","C","C"))
df <- data.frame(X,Y,Attr)
coordinates(df) <- c("X", "Y")
proj4string(df) <- CRS("+proj=longlat
+datum=WGS84 +ellps=WGS84 +towgs84=0,0,0")
select.Attr<-
names(table(df$Attr)[table(df$Attr)>1])
for(i in select.Attr){
X <- subset(df,Attr == i)
print(X)
}
Any suggestions?
best regards,
/johannees
Johannes, if spdf is a spatial points data frame, you can try: spdf.subset = spdf[spdf$Attr == i, ] HTH, ken