GeoHash 库
GeoHash
Geohash library for cplusplus.
GeoHash是空間索引的一種方式,特別適合點數據,而對線、面數據采用R樹索引更有優勢。
Basic Methods
#include <catch2/catch.hpp> #include "cgeohash.hpp"size_t precision = 12; double longitude = 112.5584; double latitude = 37.8324; GeoHash::string_type geostr("ww8p1r4t8"); GeoHash::string_type geo_neighbor("dqcjq");TEST_CASE("Test geohash encode & decode method") {SECTION("Test geohash encode method") {GeoHash::string_type out;GeoHash::encode(latitude, longitude, 9, out);REQUIRE(geostr == out);} }TEST_CASE("Test geohash decode method") {GeoHash::DecodedHash out = GeoHash::decode(geostr);//var diff = Math.abs(latitude - actual) < 0.0001REQUIRE(abs(latitude - out.latitude) <= out.latitude_err);REQUIRE(abs(longitude - out.longitude) <= out.longitude_err); }TEST_CASE("Test geohash neighbor method:finds neighbor to the north") {const int dir[2] = { 1,0 };GeoHash::string_type actual = GeoHash::neighbor(geo_neighbor, dir);GeoHash::string_type expected("dqcjw");REQUIRE(actual == expected); }TEST_CASE("Test geohash neighbor method:finds neighbor to the south-west") {const int dir[2] = { -1,-1 };GeoHash::string_type actual = GeoHash::neighbor(geo_neighbor, dir);GeoHash::string_type expected("dqcjj");REQUIRE(actual == expected); }TEST_CASE("Test decodes string to bounded box") {GeoHash::DecodedBBox box= GeoHash::decode_bbox(geostr);//[37.83236503601074,112.55836486816406,37.83240795135498,112.5584077835083];REQUIRE((latitude>=box.minlat && latitude <= box.maxlat));REQUIRE((longitude>=box.minlon && longitude<=box.maxlon)); }Reference
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