rgeos: Interface to Geometry Engine - Open Source (GEOS)

GEOSインターフェース

> library(rgeos)

バージョン: 0.3.21

関数名	概略
`Ring-class`	Class "Ring"
`SpatialCollections`	create SpatialCollections
`SpatialCollections-class`	Class "SpatialCollections"
`SpatialRings`	create SpatialRings or SpatialRingsDataFrame
`SpatialRings-class`	Class "SpatialRings"
`SpatialRingsDataFrame-class`	Class "SpatialRingsDataFrame"
`createSPComment`	RGEOS Polygon Hole Comment Functions
`gArea`	Area of Geometry
`gBoundary`	Boundary of Geometry
`gBuffer`	Buffer Geometry
`gCentroid`	Centroid of Geometry
`gContains`	Geometry Relationships - Contains and Within
`gConvexHull`	Convex Hull of Geometry
`gCrosses`	Geometry Relationships - Crosses and Overlaps
`gDelaunayTriangulation`	Compute Delaunay triangulation between points
`gDifference`	Geometry Difference
`gDistance`	Distance between geometries
`gEnvelope`	Envelope of Geometry
`gEquals`	Geometry Relationships - Equality
`gIntersection`	Geometry Intersections
`gIntersects`	Geometry Relationships - Intersects and Disjoint
`gIsEmpty`	Is Geometry Empty?
`gIsRing`	Is Geometry a Ring?
`gIsSimple`	Is Geometry Simple?
`gIsValid`	Is Geometry Valid?
`gLength`	Length of Geometry
`gNode`	Linestring Noder
`gPointOnSurface`	Point on Surface of Geometry
`gPolygonize`	Linestring Polygonizer
`gRelate`	Geometry Relationships - Intersection Matrix Pattern (DE-9IM)
`gSimplify`	Simplify Geometry
`gSymdifference`	Geometry Symmetric Difference
`gTouches`	Geometry Relationships - Touches
`gUnion`	Geometry Union
`getScale`	RGEOS Utility Functions
`gpc.poly-class`	Class "gpc.poly"
`gpc.poly.nohole-class`	Class "gpc.poly.nohole"
`new-generics`	Generics/Methods for polygon objects
`poly_findInBoxGEOS`	Experimental Functions
`polyfile`	Read/Write polygon data
`polygonsLabel`	Compute optimal label positions for polygons
`readWKT`	RGEOS WKT Functions

gCentroid

重心を求める

Arguments

spgeom
byid
id

> gCentroid(spgeom, byid = FALSE, id = NULL)