problem writing GML file
Hi Barry,
Dear r-sig-geo,
I was able to make a SpatialPointsDataFrame just fine with the following commands.
library(rgdal)
coordinates(floras) = c('long.cent.W','lat.cent.N')
class(floras)
[1] "SpatialPointsDataFrame" attr(,"package") [1] "sp" but when I run writeOGR, I get an error
writeOGR(floras,paste(getwd(),'florasTEST.gml',sep='/'),'floras', driver = 'GML')
Error in writeOGR(floras, paste(getwd(), "florasTEST.gml", sep = "/"), ?: ?unknown data type
That's weird - writeOGR looks like it should output the type and class of the column when it gets this problem: else stop(paste(dfcls[i], dftof[i], "unknown data type")) ?- unless you're on a different version. Try running writeOGR in debug mode - do: debug(writeOGR) then run your writeOGR function call. Hit return to step a line at a time, and inspect variables. Or how about cutting some of your variables out and seeing what fixes it/breaks it? your sp object only seemed to have factors, numbers, and logicals and so writeOGR shouldnt have any problem with it...
Thanks for the advice! debug() helped me figure it out. If I
understand correctly it was because I did have a logical. As I read it
the file can't have a logical.
...
dfcls <- sapply(slot(obj, "data"), function(x) class(x)[1])
known <- c("numeric", "character", "factor", "POSIXt", "integer")
if (!all(dfcls %in% known))
stop("unknown data type")
....
When I removed the logical column it worked just fine.
Thanks again for all of your help,
Michael
Barry -- blog: http://geospaced.blogspot.com/ web: http://www.maths.lancs.ac.uk/~rowlings web: http://www.rowlingson.com/ twitter: http://twitter.com/geospacedman pics: http://www.flickr.com/photos/spacedman
Michael Denslow I.W. Carpenter Jr. Herbarium [BOON] Department of Biology Appalachian State University Boone, North Carolina U.S.A. -- AND -- Communications Manager Southeast Regional Network of Expertise and Collections sernec.org 36.214177, -81.681480 +/- 3103 meters