as.psp: Coercion between sp objects and spatstat psp objects

In maptools: Tools for Handling Spatial Objects

Coercion between sp objects and spatstat psp objects

Description

Functions to convert between spatstats planar segment pattern (psp) format and various sp line formats. S4-style as() coercion can be used as well.

Usage

as.psp.Line(from, ..., window=NULL, marks=NULL, fatal)
as.psp.Lines(from, ..., window=NULL, marks=NULL, fatal)
as.psp.SpatialLines(from, ..., window=NULL, marks=NULL, characterMarks
                 = FALSE, fatal)
as.psp.SpatialLinesDataFrame(from, ..., window=NULL, marks=NULL, fatal)
as.SpatialLines.psp(from)

Arguments

from	object to coerce from
...	ignored
window	window of class owin as defined in the spatstat package
marks	marks as defined in the spatstat package
characterMarks	default FALSE, if TRUE, do not convert NULL marks to factor from character
fatal	formal coercion argument; ignored

Methods

coerce

signature(from = "Line", to = "psp")

coerce

signature(from = "Lines", to = "psp")

coerce

signature(from = "SpatialLines", to = "psp")

coerce

signature(from = "SpatialLinesDataFrame", to = "psp")

coerce

signature(from = "psp", to = "SpatialLines")

Warning

In spatstat all spatial objects are assumed to be planar. This means that spatstat is not designed to work directly with geographic (longitude and latitude) coordinates. If a sp object is declared to have geographic (unprojected) coordinates maptools refuses to convert directly to spatstat format. Rather, these should be projected first using e.g. spTransform. If you know what you are doing, and really want to force coercion, you can overwrite the proj4string of the sp object with NA, proj4string(x) <- CRS(NA), which will fool the system to think that the data is in local planar coordinates. This is probably not a good idea!

Author(s)

Edzer Pebesma [e-mail], Roger Bivand

Examples

run <- FALSE
if (require("spatstat.geom", quietly=TRUE)) run <- TRUE
if (run) {
data(meuse.riv)
mr <- Line(meuse.riv)
mr_psp <- as(mr, "psp")
mr_psp
}
if (run) {
plot(mr_psp)
}
if (run) {
xx_back <- as(mr_psp, "SpatialLines")
plot(xx_back)
}
if (run) {
xx <- readShapeLines(system.file("shapes/fylk-val.shp", package="maptools")[1],
 proj4string=CRS("+proj=utm +zone=33 +ellps=WGS84"))
xx_psp <- as(xx["LENGTH"], "psp")
xx_psp
}
if (run) {
plot(xx_psp)
}
if (run) {
xx_back <- as(xx_psp, "SpatialLines")
plot(xx_back)
}
if (run) {
xx <- readShapeLines(system.file("shapes/fylk-val-ll.shp", package="maptools")[1], 
 proj4string=CRS("+proj=longlat +ellps=WGS84"))
try(xx_psp <- as(xx["LENGTH"], "psp"))
}

maptools documentation built on Oct. 3, 2023, 3:01 p.m.