The goal of libgeos is to provide access to the Geometry Engine, Open Source (GEOS) library.
wkt <- libgeos:::wkt ## character vector
wkb <- libgeos:::wkb ## list of raw vectors
## wkt to wkt is single-element vector
libgeos:::geos_test_roundtrip_wkt(wkt[[1]])
#> [1] "MULTIPOLYGON (((-81.4727554321289062 36.2343559265137003, -81.5408401489257955 36.2725067138672017, -81.5619812011719034 36.2735939025878977, -81.6330642700195028 36.3406867980957031, -81.7410736083983949 36.3917846679687997, -81.6982803344726989 36.4717788696288991, -81.7027969360351989 36.5193405151366974, -81.6699981689452983 36.5896492004395029, -81.3452987670898011 36.5728645324707031, -81.3475418090820028 36.5379142761229971, -81.3247756958007955 36.5136795043945028, -81.3133239746094034 36.4806976318359020, -81.2662353515625000 36.4372062683104971, -81.2628402709960938 36.4050407409667969, -81.2406921386719034 36.3794174194336009, -81.2398910522460938 36.3653640747070028, -81.2642440795898011 36.3524131774901988, -81.3289947509766051 36.3635025024413991, -81.3613739013672017 36.3531608581542969, -81.3656921386719034 36.3390502929687997, -81.3541336059570028 36.2997169494628977, -81.3674545288085938 36.2786979675292969, -81.4063873291016051 36.2850532531737997, -81.4123306274414062 36.2672920227050994, -81.4310379028320028 36.2607192993163991, -81.4528884887695028 36.2395858764648011, -81.4727554321289062 36.2343559265137003)))"
## comparison not exact
libgeos:::geos_test_roundtrip_wkt(wkt[[1]]) == wkt[[1]]
#> [1] FALSE
## wkb to wkb is a single-element list
libgeos:::geos_test_roundtrip_wkb(wkb[1])
#> [[1]]
#> [1] 01 06 00 00 00 01 00 00 00 01 03 00 00 00 01 00 00 00 1b 00 00 00 00 00 00
#> [26] a0 41 5e 54 c0 00 00 00 60 ff 1d 42 40 00 00 00 20 9d 62 54 c0 00 00 00 80
#> [51] e1 22 42 40 00 00 00 80 f7 63 54 c0 00 00 00 20 05 23 42 40 00 00 00 20 84
#> [76] 68 54 c0 00 00 00 a0 9b 2b 42 40 00 00 00 c0 6d 6f 54 c0 00 00 00 00 26
#> [ reached getOption("max.print") -- omitted 355 entries ]
## comparison exact
all(libgeos:::geos_test_roundtrip_wkb(wkb[1])[[1]] == wkb[[1]])
#> [1] TRUE
libgeos:::geos_capi_version()
#> [1] "1.13.1"
libgeos:::geos_version_impl()
#> [1] "3.8.0-CAPI-1.13.1 "
try(libgeos:::geos_test_throw_error(), silent = TRUE)
# list
libgeos:::geos_wkb_is_parseable(wkb[1])
#> [1] TRUE
## atomic
libgeos:::geos_wkt_is_parseable(wkt[[1]])
#> [1] TRUE
## list to atomic
libgeos:::geos_wkb_to_wkt(wkb[1])
#> [1] "MULTIPOLYGON (((-81.4727554321289062 36.2343559265136719, -81.5408401489257812 36.2725067138671875, -81.5619812011718750 36.2735939025878906, -81.6330642700195312 36.3406867980957031, -81.7410736083984375 36.3917846679687500, -81.6982803344726562 36.4717788696289062, -81.7027969360351562 36.5193405151367188, -81.6699981689453125 36.5896492004394531, -81.3452987670898438 36.5728645324707031, -81.3475418090820312 36.5379142761230469, -81.3247756958007812 36.5136795043945312, -81.3133239746093750 36.4806976318359375, -81.2662353515625000 36.4372062683105469, -81.2628402709960938 36.4050407409667969, -81.2406921386718750 36.3794174194335938, -81.2398910522460938 36.3653640747070312, -81.2642440795898438 36.3524131774902344, -81.3289947509765625 36.3635025024414062, -81.3613739013671875 36.3531608581542969, -81.3656921386718750 36.3390502929687500, -81.3541336059570312 36.2997169494628906, -81.3674545288085938 36.2786979675292969, -81.4063873291015625 36.2850532531738281, -81.4123306274414062 36.2672920227050781, -81.4310379028320312 36.2607192993164062, -81.4528884887695312 36.2395858764648438, -81.4727554321289062 36.2343559265136719)))"
## atomic to list
libgeos:::geos_wkt_to_wkb(wkt[[1]])
#> [[1]]
#> [1] 01 06 00 00 00 01 00 00 00 01 03 00 00 00 01 00 00 00 1b 00 00 00 00 00 00
#> [26] a0 41 5e 54 c0 04 00 00 60 ff 1d 42 40 01 00 00 20 9d 62 54 c0 02 00 00 80
#> [51] e1 22 42 40 02 00 00 80 f7 63 54 c0 01 00 00 20 05 23 42 40 fe ff ff 1f 84
#> [76] 68 54 c0 00 00 00 a0 9b 2b 42 40 fd ff ff bf 6d 6f 54 c0 07 00 00 00 26
#> [ reached getOption("max.print") -- omitted 355 entries ]
## example from DD's blog
libgeos:::intersect_wkt(wkt[[1]], wkt[[2]], 1L)
#> [1] "MULTILINESTRING ((-81.3 36.6, -81.3 36.5), (-81.3 36.5, -81.3 36.5), (-81.3 36.5, -81.3 36.5), (-81.3 36.5, -81.3 36.4), (-81.3 36.4, -81.3 36.4), (-81.3 36.4, -81.2 36.4), (-81.2 36.4, -81.2 36.4))"
## new example with wkb
libgeos:::intersect_wkb(wkb[[1]], wkb[[2]])
#> [1] 01 05 00 00 00 07 00 00 00 01 02 00 00 00 02 00 00 00 00 00 00 60 19 56 54
#> [26] c0 00 00 00 a0 53 49 42 40 00 00 00 20 3e 56 54 c0 00 00 00 60 da 44 42 40
#> [51] 01 02 00 00 00 02 00 00 00 00 00 00 20 3e 56 54 c0 00 00 00 60 da 44 42 40
#> [76] 00 00 00 20 c9 54 54 c0 00 00 00 40 c0 41 42 40 01 02 00 00 00 02 00 00
#> [ reached getOption("max.print") -- omitted 197 entries ]Please note that the libgeos project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.