How do I read/work with PolyLineZM with maptools/sp?
Edzer: Thank you for your suggestions, but it doesn't help much. It does not recover either Z or M as attributes or anyhow else.
p <- as(s, "SpatialPointsDataFrame") names(p)
[1] "Id" "Lines.NR" "Lines.ID" "Line.NR"
slotNames(p)
[1] "data" "coords.nrs" "coords" "bbox" "proj4string"
head(p at coords)
coords.x1 coords.x2 [1,] 408794.5 4893921 [2,] 409088.3 4893599 [3,] 409165.2 4893484 [4,] 409434.7 4893214 [5,] 409684.9 4893060 [6,] 409742.6 4893060
head(p at data)
Id Lines.NR Lines.ID Line.NR 0 1 1 0 1 0.1 1 1 0 1 0.2 1 1 0 1 0.3 1 1 0 1 0.4 1 1 0 1 0.5 1 1 0 1
p$Z
NULL
p$z
NULL I double checked that I'm working with correct shapefile that has Z values. Mikhail
-----Original Message----- From: Edzer Pebesma [mailto:edzer.pebesma at uni-muenster.de] Sent: Monday, May 16, 2011 1:29 PM To: Mikhail Titov Cc: r-sig-geo at r-project.org Subject: Re: [R-sig-Geo] How do I read/work with PolyLineZM with maptools/sp? On 05/16/2011 08:22 PM, Mikhail Titov wrote:
I would try s$M and s$Z to access M and Z when they are attributes.
But what do I do when they are not? It can work for points, but not a
line as I can't have attributes for individual points of a line. I would prefer not to do any extra conversions in GIS before using R.
as(s, "SpatialPointsDataFrame")
Do I get it right that for now it is better to stick with shapefiles to
read PolylineZM?
Mikhail
-- Edzer Pebesma Institute for Geoinformatics (ifgi), University of M?nster Weseler Stra?e 253, 48151 M?nster, Germany. Phone: +49 251 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de http://www.52north.org/geostatistics e.pebesma at wwu.de