rgeos (version 0.6-4)

rgeos-deprecated: Deprecated functions and methods

Description

Cumulative deprecated functions and methods from rgeos prior to package retirement/archiving during 2023.

Usage

gBuffer(spgeom, byid=FALSE, id=NULL, width=1.0, quadsegs=5, capStyle="ROUND",
 joinStyle="ROUND", mitreLimit=1.0)
gDifference(spgeom1, spgeom2, byid=FALSE, id=NULL, drop_lower_td=FALSE,
 unaryUnion_if_byid_false=TRUE, checkValidity=NULL)
gSymdifference(spgeom1, spgeom2, byid=FALSE, id=NULL, drop_lower_td=FALSE,
 unaryUnion_if_byid_false=TRUE, checkValidity=NULL)
gIntersection(spgeom1, spgeom2, byid=FALSE, id=NULL, drop_not_poly,
 drop_lower_td=FALSE, unaryUnion_if_byid_false=TRUE, checkValidity=NULL)
gUnion(spgeom1, spgeom2, byid=FALSE, id=NULL, drop_lower_td=FALSE,
 unaryUnion_if_byid_false=TRUE, checkValidity=NULL)

Arguments

spgeom

sp object as defined in package sp

byid

Logical determining if the function should be applied across subgeometries (TRUE) or the entire object (FALSE)

id

Character vector defining id labels for the resulting geometries, if unspecified returned geometries will be labeled based on their parent geometries' labels.

width

Distance from original geometry to include in the new geometry. Negative values are allowed. Either a numeric vector of length 1 when byid is FALSE; if byid is TRUE: of length 1 replicated to the number of input geometries, or of length equal to the number of input geometries

quadsegs

Number of line segments to use to approximate a quarter circle.

capStyle

Style of cap to use at the ends of the geometry. Allowed values: ROUND,FLAT,SQUARE

joinStyle

Style to use for joints in the geometry. Allowed values: ROUND,MITRE,BEVEL

mitreLimit

Numerical value that specifies how far a joint can extend if a mitre join style is used.

spgeom1, spgeom2

sp objects as defined in package sp

drop_lower_td

default FALSE; if TRUE, objects will be dropped from output GEOMETRYCOLLECTION objects to simplify output if their topological dinension is less than the minimum topological dinension of the input objects.

unaryUnion_if_byid_false

default TRUE; if byid takes a FALSE in either position, the subgeometries are combined first to avoid possible topology exceptions (change in 0.3-13, previous behaviour did not combine subgeometries, and may be achieved by setting this argument FALSE

checkValidity

default NULL, integer 0L (no action), 1L (check), 2L (check and try to buffer by zero distance to repair). If NULL, a value set to 0L for GEOS < 3.7.2, 1L for GEOS >= 3.7.2 is read from values assigned on load. Error meesages from GEOS do not say clearly which object fails if a topology exception is encountered. If this argument is > 0L, gIsValid is run on each in turn

drop_not_poly

deprecated argument, use drop_lower_td

Examples

p1 = readWKT("POLYGON((0 1,0.95 0.31,0.59 -0.81,-0.59 -0.81,-0.95 0.31,0 1))")
p2 = readWKT("POLYGON((2 2,-2 2,-2 -2,2 -2,2 2),(1 1,-1 1,-1 -1,1 -1,1 1))")

par(mfrow=c(2,3))
plot(gBuffer(p1,width=-0.2),col='black',xlim=c(-1.5,1.5),ylim=c(-1.5,1.5))
plot(p1,border='blue',lwd=2,add=TRUE);title("width: -0.2")
plot(gBuffer(p1,width=0),col='black',xlim=c(-1.5,1.5),ylim=c(-1.5,1.5))
plot(p1,border='blue',lwd=2,add=TRUE);title("width: 0")
plot(gBuffer(p1,width=0.2),col='black',xlim=c(-1.5,1.5),ylim=c(-1.5,1.5))
plot(p1,border='blue',lwd=2,add=TRUE);title("width: 0.2")

plot(gBuffer(p2,width=-0.2),col='black',pbg='white',xlim=c(-2.5,2.5),ylim=c(-2.5,2.5))
plot(p2,border='blue',lwd=2,add=TRUE);title("width: -0.2")
plot(gBuffer(p2,width=0),col='black',pbg='white',xlim=c(-2.5,2.5),ylim=c(-2.5,2.5))
plot(p2,border='blue',lwd=2,add=TRUE);title("width: 0")
plot(gBuffer(p2,width=0.2),col='black',pbg='white',xlim=c(-2.5,2.5),ylim=c(-2.5,2.5))
plot(p2,border='blue',lwd=2,add=TRUE);title("width: 0.2")

p3 <- readWKT(paste("GEOMETRYCOLLECTION(",
 "POLYGON((0 1,0.95 0.31,0.59 -0.81,-0.59 -0.81,-0.95 0.31,0 1)),",
 "POLYGON((2 2,-2 2,-2 -2,2 -2,2 2),(1 1,-1 1,-1 -1,1 -1,1 1)))"))

par(mfrow=c(1,1))
plot(gBuffer(p3, byid=TRUE, width=c(-0.2, -0.1)),col='black',pbg='white',
xlim=c(-2.5,2.5),ylim=c(-2.5,2.5))
plot(p3,border=c('blue', 'red'),lwd=2,add=TRUE);title("width: -0.2, -0.1")
library(sp)
p3df <- SpatialPolygonsDataFrame(p3, data=data.frame(i=1:length(p3),
 row.names=row.names(p3)))
dim(p3df)
row.names(p3df)
dropEmpty = gBuffer(p3df, byid=TRUE, id=letters[1:nrow(p3df)], width=c(-1, 0))
dim(dropEmpty)
row.names(dropEmpty)
row.names(slot(dropEmpty, "data"))
plot(dropEmpty, col='black', pbg='white', xlim=c(-2.5,2.5),ylim=c(-2.5,2.5))
plot(p3df,border=c('blue'),lwd=2,add=TRUE);title("width: -1, 0")
par(mfrow=c(2,3))


#Style options
l1 = readWKT("LINESTRING(0 0,1 5,4 5,5 2,8 2,9 4,4 6.5)")
par(mfrow=c(2,3))
plot(gBuffer(l1,capStyle="ROUND"));plot(l1,col='blue',add=TRUE);title("capStyle: ROUND")
plot(gBuffer(l1,capStyle="FLAT"));plot(l1,col='blue',add=TRUE);title("capStyle: FLAT")
plot(gBuffer(l1,capStyle="SQUARE"));plot(l1,col='blue',add=TRUE);title("capStyle: SQUARE")

plot(gBuffer(l1,quadsegs=1));plot(l1,col='blue',add=TRUE);title("quadsegs: 1")
plot(gBuffer(l1,quadsegs=2));plot(l1,col='blue',add=TRUE);title("quadsegs: 2")
plot(gBuffer(l1,quadsegs=5));plot(l1,col='blue',add=TRUE);title("quadsegs: 5")



l2 = readWKT("LINESTRING(0 0,1 5,3 2)")
par(mfrow=c(2,3))
plot(gBuffer(l2,joinStyle="ROUND"));plot(l2,col='blue',add=TRUE);title("joinStyle: ROUND")
plot(gBuffer(l2,joinStyle="MITRE"));plot(l2,col='blue',add=TRUE);title("joinStyle: MITRE")
plot(gBuffer(l2,joinStyle="BEVEL"));plot(l2,col='blue',add=TRUE);title("joinStyle: BEVEL")

plot(gBuffer(l2,joinStyle="MITRE",mitreLimit=0.5));plot(l2,col='blue',add=TRUE)
 title("mitreLimit: 0.5")
plot(gBuffer(l2,joinStyle="MITRE",mitreLimit=1));plot(l2,col='blue',add=TRUE)
 title("mitreLimit: 1")
plot(gBuffer(l2,joinStyle="MITRE",mitreLimit=3));plot(l2,col='blue',add=TRUE)
 title("mitreLimit: 3")
x = readWKT("POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))")
y = readWKT("POLYGON ((3 3, 7 3, 7 7, 3 7, 3 3))")

d = gDifference(x,y)
plot(d,col='red',pbg='white')

# Empty geometry since y is completely contained with x
d2 = gDifference(y,x)
pol <- readWKT(paste("POLYGON((-180 -20, -140 55, 10 0, -140 -60, -180 -20),",
 "(-150 -20, -100 -10, -110 20, -150 -20))"))
library(sp)
GT <- GridTopology(c(-175, -85), c(10, 10), c(36, 18))
gr <- as(as(SpatialGrid(GT), "SpatialPixels"), "SpatialPolygons")
try(res <- gIntersection(pol, gr, byid=TRUE))
res <- gIntersection(pol, gr, byid=TRUE, drop_lower_td=TRUE)
# Robert Hijmans difficult intersection case
load(system.file("test_cases/polys.RData", package="rgeos"))
try(res <- gIntersection(a, b, byid=TRUE))
res <- gIntersection(a, b, byid=TRUE, drop_lower_td=TRUE)
unlist(sapply(slot(res, "polygons"), function(p) sapply(slot(p, "Polygons"), slot, "area")))
# example from Pius Korner 2015-10-25
poly1 <- SpatialPolygons(list(Polygons(list(Polygon(coords=matrix(c(0, 0, 2, 2, 0, 1, 1, 0),
 ncol=2, byrow=FALSE))), ID=c("a")), Polygons(list(Polygon(coords=matrix(c(0, 0, 2, 2, 2, 3, 3, 2),
 ncol=2, byrow=FALSE))), ID=c("b"))))
poly2 <- SpatialPolygons(list(Polygons(list(Polygon(coords=matrix(c(0, 0, 2, 2,
 1, 1, 1, 3, 3, 0, 0, 2), ncol=2, byrow=FALSE))), ID=c("c"))))
plot(poly1, border="orange")
plot(poly2, border="blue", add=TRUE, lty=2, density=8, angle=30, col="blue")
gI <- gIntersection(poly1, poly2, byid=TRUE, drop_lower_td=TRUE)
plot(gI, add=TRUE, border="red", lwd=3)
oT <- get_RGEOS_polyThreshold()
oW <- get_RGEOS_warnSlivers()
oD <- get_RGEOS_dropSlivers()
set_RGEOS_polyThreshold(1e-3)
set_RGEOS_warnSlivers(TRUE)
res1 <- gIntersection(a, b, byid=TRUE, drop_lower_td=TRUE)
unlist(sapply(slot(res1, "polygons"), function(p) sapply(slot(p, "Polygons"), slot, "area")))
set_RGEOS_dropSlivers(TRUE)
res2 <- gIntersection(a, b, byid=TRUE, drop_lower_td=TRUE)
unlist(sapply(slot(res2, "polygons"), function(p) sapply(slot(p, "Polygons"), slot, "area")))
set_RGEOS_dropSlivers(FALSE)
oo <- gUnaryUnion(res1, c(rep("1", 3), "2", "3", "4"), checkValidity=2L)
unlist(sapply(slot(oo, "polygons"), function(p) sapply(slot(p, "Polygons"), slot, "area")))
ooo <- gIntersection(b, oo, byid=TRUE, checkValidity=2L)
gArea(ooo, byid=TRUE)
unlist(sapply(slot(ooo, "polygons"), function(p) sapply(slot(p, "Polygons"), slot, "area")))
set_RGEOS_dropSlivers(TRUE)
ooo <- gIntersection(b, oo, byid=TRUE, checkValidity=2L)
gArea(ooo, byid=TRUE)
unlist(sapply(slot(ooo, "polygons"), function(p) sapply(slot(p, "Polygons"), slot, "area")))
set_RGEOS_polyThreshold(oT)
set_RGEOS_warnSlivers(oW)
set_RGEOS_dropSlivers(oD)
# see thread https://stat.ethz.ch/pipermail/r-sig-geo/2015-September/023468.html
Pol1=rbind(c(0,0),c(0,10),c(10,10),c(10,0),c(0,0))
Pol2=rbind(c(0,0),c(10,0),c(10,-10),c(0,-10),c(0,0))
library(sp)
Pols1=Polygons(list(Polygon(Pol1)),"Pols1")
Pols2=Polygons(list(Polygon(Pol2)),"Pols2")
MyLay=SpatialPolygons(list(Pols1,Pols2))
Pol1l=Pol1+0.5
Pol2l=Pol2+0.5
Pols1l=Polygons(list(Polygon(Pol1l)),"Pols1l")
Pols2l=Polygons(list(Polygon(Pol2l)),"Pols2l")
MyLayl=SpatialPolygons(list(Pols1l,Pols2l))
inter=gIntersection(MyLay, MyLayl)
plot(MyLay)
plot(MyLayl,add=TRUE)
plot(inter, add=TRUE, border="green")
try(gIntersection(MyLay, MyLayl, unaryUnion_if_byid_false=FALSE))
Pol1=rbind(c(0,0),c(0,1),c(1,1),c(1,0),c(0,0))
Pol2=rbind(c(0,0),c(1,0),c(1,-1),c(0,-1),c(0,0))
Pols1=Polygons(list(Polygon(Pol1)),"Pols1")
Pols2=Polygons(list(Polygon(Pol2)),"Pols2")
MyLay=SpatialPolygons(list(Pols1,Pols2))
Pol1l=Pol1+0.1
Pol2l=Pol2+0.1
Pols1l=Polygons(list(Polygon(Pol1l)),"Pols1l")
Pols2l=Polygons(list(Polygon(Pol2l)),"Pols2l")
MyLayl=SpatialPolygons(list(Pols1l,Pols2l))
inter=gIntersection(MyLay, MyLayl, unaryUnion_if_byid_false=FALSE)
gEquals(inter, MyLay)
inter1=gIntersection(MyLay, MyLayl, unaryUnion_if_byid_false=TRUE)
gEquals(inter1, MyLay)
gEquals(inter, inter1)
plot(MyLay, ylim=c(-1, 1.1))
plot(MyLayl, add=TRUE)
plot(inter, angle=45, density=10, add=TRUE)
plot(inter1, angle=135, density=10, add=TRUE)
inter2=gIntersection(MyLay, MyLayl)
gEquals(inter2, MyLay)
gEquals(inter1, inter2)
x = readWKT("POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))")
y = readWKT("POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))")

d = gSymdifference(x,y)
plot(d,col='red',pbg='white')