I want to discard few polygons from an sp. poly. DF. I'm trying things such as: > str(x,max.level=2) Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots ..@ data :'data.frame': 42 obs. of 9 variables: ..@ polygons :List of 42 ..@ plotOrder : int [1:42] 32 35 38 1 8 29 33 26 27 31 ... ..@ bbox : num [1:2, 1:2] 437951 4605986 459732 4633538 .. ..- attr(*, "dimnames")=List of 2 ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slots > > x <- subset(x,row.names(x)!="1") Error in `[.data.frame`(x at data, i, j, ..., drop = FALSE) : undefined columns selected but the output of row.names(x)!="1" is correct, what am I doing wrong? Is subset() (from maptools) not appropriate for objects of type SPDF ? Thanks Agus
subseting an spatial polygons data frame
2 messages · Agustin Lobo
Answering to myself: This works fine: plot(x[x at data$CODI_EQP!=413,]) plot(x[row.names(x)==20,]) Agus
Agustin Lobo wrote:
I want to discard few polygons from an sp. poly. DF. I'm trying things such as:
> str(x,max.level=2)
Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots ..@ data :'data.frame': 42 obs. of 9 variables: ..@ polygons :List of 42 ..@ plotOrder : int [1:42] 32 35 38 1 8 29 33 26 27 31 ... ..@ bbox : num [1:2, 1:2] 437951 4605986 459732 4633538 .. ..- attr(*, "dimnames")=List of 2 ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slots
> > x <- subset(x,row.names(x)!="1")
Error in `[.data.frame`(x at data, i, j, ..., drop = FALSE) : undefined columns selected but the output of row.names(x)!="1" is correct, what am I doing wrong? Is subset() (from maptools) not appropriate for objects of type SPDF ? Thanks Agus