rangeMapper (version 0.2-8)

WKT2SpatialPolygonsDataFrame: Convert WKT polygons to SpatialPolygonsDataFrame

Description

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

Usage

WKT2SpatialPolygonsDataFrame(dat, geom, id)

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 rgeos::gUnionCascaded.

Value

• a SpatialPolygonsDataFrame object.

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))