I´m looking for a way to create a SpatialPolygonsDataFrame from a list of SpatialPolygons?
In the following there´s an example of a list of Polygons from which a SpatialPolygonsDataFrame, containing all Polygons of the list, should be created.
EDIT: The SpatialPolygonsDataFrame must be created from the list of SpatialPolygons! As my original data doesn´t contains SpatialPolygons as separate values but the list of SpatialPolygons. The way I received this list is different form the one in the example. I posted the example to show the data structure of the list.
example of a list of SpatialPolygons taken from https://stat.ethz.ch/pipermail/r-sig-geo/2013-January/017225.html:
library(sp)
grd <- GridTopology(c(0.5, 0.5), c(1, 1), c(6, 6))
Spol <- as(grd, "SpatialPolygons")
list_of_SPolsu <- lapply(slot(Spol, "polygons"), function(x)
SpatialPolygons(list(x)))
list_of_SPols <- lapply(slot(Spol, "polygons"), function(x) {
Pol <- x
slot(Pol, "ID") <- "1"
SpatialPolygons(list(Pol))
})
Regards!
Try this:
#Creating a dataframe with Spol IDs
Spol_df<- as.data.frame(sapply(slot(Spol, "polygons"), function(x) slot(x, "ID")))
#Making the IDs row names
row.names(Spol_df) <- sapply(slot(Spol, "polygons"), function(x) slot(x, "ID"))
# Making the spatial polygon data frame
Spol_SPDF <- SpatialPolygonsDataFrame(Spol, data =Spol_df)
Let me know if it worked
Just to make the answer complete according to the Edit in the question... The solution on how to make a SpatialPolygon from a list of polygons comes from the provided link:
#Getting polygon IDs
IDs <- sapply(list_of_SPols, function(x)
slot(slot(x, "polygons")[[1]], "ID"))
#Checking
length(unique(IDs)) == length(list_of_SPols)
#Making SpatialPolygons from list of polygons
Spol <- SpatialPolygons(lapply(list_of_SPols,
function(x) slot(x, "polygons")[[1]]))