WKT2SpatialPolygonsDataFrame: Convert WKT polygons to SpatialPolygonsDataFrame

In valcu/rangeMapper: A Platform for the Study of Macro-Ecology of Life History Traits

Description

Convert a data.frame containing WKT polygons to a SpatialPolygonsDataFrame.

Extract vertices from a SpatialPolygonsDataFrame and optionally applies an aggregating function to each Polygon.

Usage

WKT2SpatialPolygonsDataFrame(dat, geom, id)

vertices(object, FUN)

## S4 method for signature 'SpatialPolygons'
vertices(object, FUN)

Arguments

dat	data.frame
geom	is the name (character vector) of the column in the data.frame containing the geometry.
id	is the name (character vector) of the column in the data.frame identifying the polygon. when id is not unique then polygons are combined using gUnionCascaded.
object	An object.
FUN	A function.

Value

a SpatialPolygonsDataFrame object.

A SpatialPointsDataFrame containing an id column corresponding to each extracted Polygon.

Examples

require(rangeMapper)
require(rgeos)

# generate a few random polygons
randPoly = function(mean, sd) {
  writeWKT(
    gConvexHull(
     readWKT(paste("MULTIPOINT (",
             paste(apply(matrix(rnorm(n= 100, mean, sd), ncol = 2), 1,
             paste, collapse = ' '), collapse = ","), ")"))))
}
n = 50
d = data.frame( nam = sample(letters, n, TRUE),
               range = mapply(randPoly, mean = sample(1:2, n, TRUE),
               sd = sample(1:2/5, n, TRUE) ))


X = WKT2SpatialPolygonsDataFrame(d, 'range', 'nam')


dbcon = rangeMap.start(file = "test.sqlite", overwrite = TRUE, dir = tempdir() )
global.bbox.save(con = dbcon, bbox = X)
gridSize.save(dbcon)
canvas.save(dbcon)
processRanges(spdf = X, con =  dbcon, ID = "nam")
rangeMap.save(dbcon)
plot(rangeMap.fetch(dbcon))

require(rangeMapper)
require(rgdal)
f = system.file(package = "rangeMapper", "extdata", "wrens", "vector")
# path to Campylorhynchus_gularis breeding range:
camgul = selectShpFiles(f, ogr = TRUE, polygons.only = TRUE)[6, ]
r = readOGR(camgul$dsn, camgul$layer)
mp = vertices(r, mean)
v = vertices(r)

plot(r)
points(mp, col = 2, pch = 3, cex = 2)
points(v, pch = 3, cex = .5)

valcu/rangeMapper documentation built on Feb. 6, 2021, 8:20 p.m.