Examples for 'rgeos::gMakeValid'

Make invalid geometries valid

Aliases: gMakeValid

Keywords: spatial

### ** Examples

# Based on test geometries from sf
run <- FALSE
if (version_GEOS0() >= "3.8.0") run <- TRUE
if (run) {
X <- readWKT("POLYGON ((0 0, 0.5 0, 0.5 0.5, 0.5 0, 1 0, 1 1, 0 1, 0 0))")
gIsValid(X)
}

Warning in RGEOSUnaryPredFunc(spgeom, byid, "rgeos_isvalid"): Ring
Self-intersection at or near point 0.5 0

[1] FALSE

if (run) {
class(X)
}

[1] "SpatialPolygons"
attr(,"package")
[1] "sp"

if (run) {
row.names(X)
}

[1] "1"

if (run) {
Y <- gMakeValid(X)
}
if (run) {
gIsValid(Y)
}

[1] TRUE

if (run) {
class(Y)
}

[1] "SpatialCollections"
attr(,"package")
[1] "rgeos"

if (run) {
plot(slot(Y, "polyobj"))
plot(slot(Y, "lineobj"), add=TRUE, col="red")
}
plot of chunk example-rgeos-gMakeValid-1
if (run) {
row.names(slot(Y, "polyobj"))
}

[1] "1"

if (run) {
row.names(slot(Y, "lineobj"))
}

[1] "1"

run <- FALSE
if (version_GEOS0() >= "3.10.0") run <- TRUE
if (run) {
JTSplot <- function(x, fill="grey90", pts="black", main="", xlim, ylim) {
  if (inherits(x, "SpatialCollections")) {
    xl <- xp <- xpl <- NULL
    if (!is.null(slot(x, "lineobj"))) xl <- slot(x, "lineobj")
    if (!is.null(slot(x, "pointobj"))) xp <- slot(x, "pointobj")
    if (!is.null(slot(x, "polyobj"))) xpl <- slot(x, "polyobj")
    if (is.null(xl)) xl <- as(xpl, "SpatialLines")
    else xl <- rbind(xl, as(xpl, "SpatialLines"))
    if (is.null(xp)) xp <- as(xl, "SpatialPoints")
    else xp <- rbind(xp, as(xl, "SpatialPoints"))
  } else {
    xl <- as(x, "SpatialLines")
    xp <- as(xl, "SpatialPoints")
  }
  plot(coordinates(xp), type="n", main=main, xlab="", ylab="", axes=FALSE, xlim=xlim, ylim=ylim)
  plot(x, col=fill, border="transparent", add=TRUE, xlim=xlim, ylim=ylim)
  plot(xl, col=pts, add=TRUE, xlim=xlim, ylim=ylim)
  plot(xp, col=pts, add=TRUE, pch=14, xlim=xlim, ylim=ylim)
}
}
if (run) {
X <- readWKT(paste0("POLYGON ((10 70, 90 70, 90 50, 30 50, 30 30, ",
 "50 30, 50 90, 70 90, 70 10, 10 10, 10 70))", sep=""))
bb <- bbox(X)
opar <- par(mfrow=c(2,2))
JTSplot(X, fill="#dfdfff", pts="#00007c", main="input", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=TRUE), fill="#ffffa4", pts="#78b400",
 main="linework", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE), fill="#ffffa4", pts="#78b400",
 main="structure", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE, keepCollapsed=TRUE), fill="#ffffa4",
 pts="#78b400", main="structure + keep collapsed", xlim=bb[1,], ylim=bb[2,])
par(opar)
}
plot of chunk example-rgeos-gMakeValid-1
if (run) {
X <- readWKT(paste0("POLYGON ((10 70, 90 70, 90 10, 10 10, 10 70), ",
 "(60 80, 50 30, 0 20, 10 30, 60 80), (30 40, 60 30, 40 0, 30 40))", sep=""))
bb <- rbind(c(0, 90), c(0, 80))
opar <- par(mfrow=c(2,2))
JTSplot(X, fill="#dfdfff", pts="#00007c", main="input", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=TRUE), fill="#ffffa4", pts="#78b400",
 main="linework", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE), fill="#ffffa4", pts="#78b400",
 main="structure", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE, keepCollapsed=TRUE), fill="#ffffa4",
 pts="#78b400", main="structure + keep collapsed", xlim=bb[1,], ylim=bb[2,])
par(opar)
}
plot of chunk example-rgeos-gMakeValid-1
if (run) {
X <- readWKT(paste0("MULTIPOLYGON (((10 90, 60 90, 60 40, 10 40, 10 90)), ",
 "((40 60, 70 60, 70 30, 40 30, 40 60)), ((20 50, 50 50, 50 20, 20 20, 20 50)))", sep=""))
bb <- bbox(X)
opar <- par(mfrow=c(2,2))
JTSplot(X, fill="#dfdfff", pts="#00007c", main="input", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=TRUE), fill="#ffffa4", pts="#78b400",
 main="linework", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE), fill="#ffffa4", pts="#78b400",
 main="structure", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE, keepCollapsed=TRUE), fill="#ffffa4",
 pts="#78b400", main="structure + keep collapsed", xlim=bb[1,], ylim=bb[2,])
par(opar)
}
plot of chunk example-rgeos-gMakeValid-1
if (run) {
X <- readWKT(paste0("MULTIPOLYGON (((10 40, 40 40, 40 10, 10 10, 10 40), ",
"(16 17, 31 32, 24 25, 16 17)), ((50 40, 50 40, 50 40, 50 40, 50 40)))", sep=""))
bb <- bbox(X)
opar <- par(mfrow=c(2,2))
JTSplot(X, fill="#dfdfff", pts="#00007c", main="input", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=TRUE), fill="#ffffa4", pts="#78b400",
 main="linework", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE), fill="#ffffa4", pts="#78b400",
 main="structure", xlim=bb[1,], ylim=bb[2,])
JTSplot(gMakeValid(X, original=FALSE, keepCollapsed=TRUE), fill="#ffffa4",
 pts="#78b400", main="structure + keep collapsed", xlim=bb[1,], ylim=bb[2,])
par(opar)
}
plot of chunk example-rgeos-gMakeValid-1
if (run) {
X <- readWKT(paste0("MULTIPOLYGON (((10 40, 40 40, 40 10, 10 10, 10 40), ",
"(16 17, 31 32, 24 25, 16 17)), ((50 40, 50 40, 50 40, 50 40, 50 40)))", sep=""))
bb <- bbox(X)
opar <- par(mfrow=c(2,2))
JTSplot(X, fill="#dfdfff", pts="#00007c", main="input", xlim=bb[1,], ylim=bb[2,])
Sys.setenv("GEOS_MAKE_VALID"="LINEWORK")
JTSplot(gMakeValid(X), fill="#ffffa4", pts="#78b400", main="linework (env-var)",
 xlim=bb[1,], ylim=bb[2,])
Sys.setenv("GEOS_MAKE_VALID"="STRUCTURE")
Sys.setenv("GEOS_MAKE_VALID_KEEPCOLLAPSED"="FALSE")
JTSplot(gMakeValid(X), fill="#ffffa4", pts="#78b400", main="structure (env-vars)",
 xlim=bb[1,], ylim=bb[2,])
Sys.setenv("GEOS_MAKE_VALID_KEEPCOLLAPSED"="TRUE")
JTSplot(gMakeValid(X), fill="#ffffa4", pts="#78b400", main="structure + keep collapsed (env-vars)",
 xlim=bb[1,], ylim=bb[2,])
par(opar)
Sys.unsetenv("GEOS_MAKE_VALID")
Sys.unsetenv("GEOS_MAKE_VALID_KEEPCOLLAPSED")

}
plot of chunk example-rgeos-gMakeValid-1
[Package rgeos version 0.5-9 Index]