topology function

Vector topology methods

makeNodes create nodes on lines

mergeLines connect lines to form polygons

removeDupNodes removes duplicate nodes in geometries and optionally rounds the coordinates

emptyGeoms returns the indices of empty (null) geometries. is.na also checks if any of the coordinates is NA.

snap makes boundaries of geometries identical if they are very close to each other. methods

## S4 method for signature 'SpatVector'
mergeLines(x)
## S4 method for signature 'SpatVector'
snap(x, y=NULL, tolerance)
## S4 method for signature 'SpatVector'
removeDupNodes(x, digits = -1)
## S4 method for signature 'SpatVector'
makeNodes(x)

Arguments

• x: SpatVector of lines or polygons
• y: SpatVector of lines or polygons to snap to. If NULL snapping is to the other geometries in x
• tolerance: numeric. Snapping tolerance (distance between geometries)
• digits: numeric. Number of digits used in rounding. Ignored if < 0

Returns

SpatVector

See Also

sharedPaths, gaps, simplifyGeom, forceCCW

Examples

p1 <- as.polygons(ext(0,1,0,1))
p2 <- as.polygons(ext(1.1,2,0,1))

p <- rbind(p1, p2)

y <- snap(p, tol=.15)
plot(p, lwd=3, col="light gray")
lines(y, col="red", lwd=2)