This is / was an experimental package and is no longer actively developped or maintained

boostgeometry

R package wrapping v1.67.0 of boost::geometry

Installation

Install the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("SymbolixAU/boostgeometry")

Examples

Area

library(boostgeometry)
bg_area("POLYGON((0 0,0 1,1 1,1 0,0 0))")
#> [1] 1
bg_area("POLYGON((0 0,0 1,1 1,1 0,0 0))", strategy = "spherical")
#> [1] 0.0003046097
bg_area("POLYGON((0 0,0 1,1 1,1 0,0 0))", strategy = "geographic")
#> [1] 12308777799

Centroid

wkt <- paste0("POLYGON((2 1.3,2.4 1.7,2.8 1.8,3.4 1.2,3.7 1.6,3.4 2,4.1 3,5.3 2.6,",
              "5.4 1.2,4.9 0.8,2.9 0.7,2 1.3),(4.0 2.0, 4.2 1.4, 4.8 1.9, 4.4 2.2, 4.0 2.0))")
bg_centroid(wkt)
#> [1] "POINT(4.04663 1.6349)"

Clear

bg_clear("POLYGON((0 0,0 1,1 1,1 0,0 0))")
#> [1] "POLYGON(())"
bg_clear("LINESTRING(0 0,1 1)")
#> [1] "LINESTRING()"
bg_clear("MULTIPOINT(0 0,1 1)")
#> [1] "MULTIPOINT()"
## points remain unchanged
bg_clear("POINT(0 0)")
#> [1] "POINT(0 0)"

Convex Hull

polygon <- paste0("POLYGON((2.0 1.3, 2.4 1.7, 2.8 1.8, 3.4 1.2, 3.7 1.6,3.4 2.0,",
                  " 4.1 3.0, 5.3 2.6, 5.4 1.2, 4.9 0.8, 2.9 0.7,2.0 1.3))")
bg_convex_hull(polygon)
#> [1] "POLYGON((2 1.3,2.4 1.7,4.1 3,5.3 2.6,5.4 1.2,4.9 0.8,2.9 0.7,2 1.3))"

Correct

bg_correct("POLYGON((0 0, 0 1, 1 1, 1 0))")
#> [1] "POLYGON((0 0,0 1,1 1,1 0,0 0))"
bg_correct("POLYGON((0 0, 0 1, 1 1, 1 0),(0.25 0.25, 0.25 0.75, 0.75 0.75, 0.75 0.25))")
#> [1] "POLYGON((0 0,0 1,1 1,1 0,0 0),(0.25 0.25,0.75 0.25,0.75 0.75,0.25 0.75,0.25 0.25))"

Crosses

x <- "LINESTRING(-1 -1, 0 0, 1 1)"
y <- c("LINESTRING(1 -1, 0 0, -1 1)", "LINESTRING(0 0, 1 1)", "LINESTRING(-1 1, 0 0, 1 -1)")
bg_crosses(x, y)
#>      [,1]  [,2] [,3]
#> [1,] TRUE FALSE TRUE

Densify

bg_densify("POLYGON((0 0,0 10,10 10,10 0,0 0),(1 1,4 1,4 4,1 4,1 1))", distance = 6)
#> [1] "POLYGON((0 0,0 5,0 10,5 10,10 10,10 5,10 0,5 0,0 0),(1 1,4 1,4 4,1 4,1 1))"
bg_densify("POLYGON((0 0,0 10,10 10,10 0,0 0),(1 1,4 1,4 4,1 4,1 1))", strategy = "spherical", distance = 0.06)
#> [1] "POLYGON((0 0,0 3.33334,0 6.66667,0 10,3.33323 10.0333,6.6668 10.0333,10 10,10 6.66666,10 3.33332,10 0,6.66666 0,3.33333 0,0 0),(1 1,4 1,4 4,1 4,1 1))"
bg_densify("POLYGON((0 0,0 10,10 10,10 0,0 0),(1 1,4 1,4 4,1 4,1 1))", strategy = "geographic", distance = 60000)
#> [1] "POLYGON((0 0,2.58027e-10 0.526362,5.16097e-10 1.05273,7.74254e-10 1.57909,1.03254e-09 2.10545,1.291e-09 2.63179,1.54968e-09 3.15815,1.80862e-09 3.6845,2.06786e-09 4.21083,2.32745e-09 4.73716,2.58743e-09 5.26349,2.84785e-09 5.7898,3.10876e-09 6.3161,3.37019e-09 6.84241,3.63219e-09 7.36869,3.89482e-09 7.89496,4.1581e-09 8.42122,4.4221e-09 8.94746,4.68687e-09 9.47369,0 10,0.526248 10.0075,1.05252 10.0142,1.57881 10.02,2.10512 10.025,2.63144 10.0292,3.15778 10.0326,3.68412 10.0351,4.21048 10.0367,4.73683 10.0376,5.26319 10.0376,5.78955 10.0367,6.3159 10.0351,6.84224 10.0326,7.36858 10.0292,7.89491 10.025,8.42121 10.02,8.94751 10.0142,9.47377 10.0075,10 10,10 6.04223,10 5.71164,10 5.38018,10 5.04791,10 4.71487,10 4.38112,10 4.0467,10 3.71166,10 3.37606,10 3.03994,10 2.70335,10 2.36635,10 2.02898,10 1.69131,10 1.35337,10 1.01523,10 0.676926,10 0.338521,10 0,9.47368 -2.31607e-08,8.94737 -4.63195e-08,8.42105 -6.94743e-08,7.89473 -9.26233e-08,7.36842 -1.15764e-07,6.8421 -1.38896e-07,6.31579 -1.62015e-07,5.78947 -1.85121e-07,5.26315 -2.08211e-07,4.73684 -2.31283e-07,4.21052 -2.54335e-07,3.68421 -2.77366e-07,3.15789 -3.00374e-07,2.63157 -3.23356e-07,2.10526 -3.4631e-07,1.57894 -3.69235e-07,1.05262 -3.92129e-07,0.526308 -4.14989e-07,0 0),(1 1,1.5 1.00019,2.00001 1.00031,2.50001 1.00034,3.00002 1.00031,3.50002 1.00019,4 1,4 1.49999,4 1.99999,4 2.49998,4 2.99997,4 3.49995,4 4,3.50001 4.00076,3.00002 4.00122,2.50002 4.00138,2.00003 4.00122,1.50004 4.00076,1 4,1 2.21955,1 1.90305,1 1.58628,1 1.2693,1 0.952137,1 1))"

Distance

points <- c("POINT(0 0)", "POINT(2 0)", "POINT(2 2)")
bg_distance(points)
#>          [,1] [,2]     [,3]
#> [1,] 0.000000    2 2.828427
#> [2,] 2.000000    0 2.000000
#> [3,] 2.828427    2 0.000000
bg_distance(points, points)
#>          [,1] [,2]     [,3]
#> [1,] 0.000000    2 2.828427
#> [2,] 2.000000    0 2.000000
#> [3,] 2.828427    2 0.000000

lines <- c("LINESTRING(1 1, 1 0, 1 -1)")
bg_distance(points, lines)
#>          [,1]
#> [1,] 1.000000
#> [2,] 1.000000
#> [3,] 1.414214
bg_distance(points, lines, "geographic")
#>          [,1]
#> [1,] 111314.0
#> [2,] 111314.0
#> [3,] 156850.3

Envelope (bounding box)

polygon <- paste0("POLYGON((2 1.3,2.4 1.7,2.8 1.8,3.4 1.2,3.7 1.6,3.4 2,4.1 3,5.3",
                  " 2.6,5.4 1.2,4.9 0.8,2.9 0.7,2 1.3), (4.0 2.0, 4.2 1.4, 4.8 1.9, 4.4 2.2, 4.0 2.0))")
bg_envelope(polygon)
#> [1] "POLYGON((2 0.7,2 3,5.4 3,5.4 0.7,2 0.7))"

bg_envelope("LINESTRING(144 -37, 145 -36)", "geographic")
#> [1] "POLYGON((144 -37,144 -36,145 -36,145 -37,144 -37))"

Is empty / simple / valid

bg_is_empty("MULTILINESTRING((0 0,0 10,10 0),(1 1,8 1,1 8))")
#> [1] 0
bg_is_simple("MULTILINESTRING((0 0,0 10,10 10,10 0,0 0),(10 10,20 20))")
#> [1] 0
bg_is_simple("LINESTRING(0 0,0 10,10 10,10 0,0 0)")
#> [1] 1
bg_is_valid("POLYGON((0 0,0 10,10 10,10 0,0 0),(0 0,9 1,9 2,0 0),(0 0,2 9,1 9,0 0),(2 9,9 2,9 9,2 9))")
#> [1] 0
bg_is_valid("POLYGON((0 0,0 10,10 10,10 0,0 0))")
#> [1] 1

Length

bg_length("LINESTRING(0 0,1 1,4 8,3 2)")
#> [1] 15.11275
bg_length("LINESTRING(0 0,1 1,4 8,3 2)", "geographic")
#> [1] 1672139

Number geometries / rings / points / segments

bg_number_geometries("LINESTRING(0 0, 0 1, 1 1, 1 0, 0 0)")
#> [1] 1
bg_number_geometries("MULTIPOLYGON(((0 0,0 10,10 0,0 0),(1 1,1 9,9 1,1 1)),((10 10,10 7,7 10,10 10)))")
#> [1] 2
bg_number_interior_rings("POLYGON((0 0,0 10,10 0,0 0),(1 1,1 2,2 1,1 1),(3 3,3 4,4 3,3 3))")
#> [1] 2
bg_number_points("MULTIPOLYGON(((0 0,0 10,10 0,0 0),(1 1,1 9,9 1,1 1)),((10 10,10 7,7 10,10 10)))")
#> [1] 12
bg_number_segments("MULTIPOLYGON(((0 0,0 10,10 0),(1 1,8 1,1 8)),((10 10,10 20,20 10)))")
#> [1] 6

Perimeter

polygon <- "POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))"
bg_perimeter(polygon)
#> [1] 4
bg_perimeter(polygon, "spherical")
#> [1] 0.06981051
bg_perimeter(polygon, "geographic")
#> [1] 443752.7

Reverse

bg_reverse("POLYGON((0 0,0 1,1 1,1 0,0 0))")
#> [1] "POLYGON((0 0,1 0,1 1,0 1,0 0))"

Simplify

polygon <- "POLYGON((0 0, 0 0.2, 0.2 0.2, 0.2 0, 0.3 0, 0.3 0.2, 0.25, 0.5, 0.1 0.4, 0 0.2, 0 0))"
bg_simplify(polygon, distance = 0.2)
#> [1] "POLYGON((0.5 0,0.1 0.4,0 0,0 0.2,0.5 0))"

Unique

bg_unique("LINESTRING(0 0,0 0,1 1,1 1,2 2)")
#> [1] "LINESTRING(0 0,1 1,2 2)"
bg_unique("POLYGON((0 0,0 0,0 5,5 5,5 5,5 5,5 0,5 0,0 0,0 0,0 0,0 0))")
#> [1] "POLYGON((0 0,0 5,5 5,5 0,0 0))"

Within

x <- c("POINT(0 0)", "LINESTRING(1 1,1 2)")
y <- c("POLYGON((-1 -1, -1 1, 1 1, 1 -1, -1 -1))", "LINESTRING(0 0, 1 1, 1 2, 2 2)",
 "POLYGON((-2 -2, -2 2, 2 2, 2 -2, -2 -2))")
bg_within(x, y)
#>       [,1]  [,2] [,3]
#> [1,]  TRUE FALSE TRUE
#> [2,] FALSE  TRUE TRUE