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Version: 3.x

Miscellaneous H3 functions

These functions include descriptions of the H3 grid system.

degsToRads

double degsToRads(double degrees);

Converts degrees to radians.

radsToDegs

double radsToDegs(double radians);

Converts radians to degrees.

hexAreaKm2

double hexAreaKm2(int res);

Average hexagon area in square kilometers at the given resolution.

hexAreaM2

double hexAreaM2(int res);

Average hexagon area in square meters at the given resolution.

cellAreaM2

double cellAreaM2(H3Index h);

Exact area of specific cell in square meters.

cellAreaRads2

double cellAreaRads2(H3Index h);

Exact area of specific cell in square radians.

edgeLengthKm

double edgeLengthKm(int res);

Average hexagon edge length in kilometers at the given resolution.

edgeLengthM

double edgeLengthM(int res);

Average hexagon edge length in meters at the given resolution.

exactEdgeLengthKm

double exactEdgeLengthKm(H3Index edge);

Exact edge length of specific unidirectional edge in kilometers.

exactEdgeLengthM

double exactEdgeLengthM(H3Index edge);

Exact edge length of specific unidirectional edge in meters.

exactEdgeLengthRads

double exactEdgeLengthRads(H3Index edge);

Exact edge length of specific unidirectional edge in radians.

numHexagons

int64_t numHexagons(int res);

Number of unique H3 indexes at the given resolution.

getRes0Indexes

void getRes0Indexes(H3Index *out);

All the resolution 0 H3 indexes. out must be an array of at least size res0IndexCount().

res0IndexCount

int res0IndexCount(void);

Number of resolution 0 H3 indexes.

getPentagonIndexes

void getPentagonIndexes(int res, H3Index *out);

All the pentagon H3 indexes at the specified resolution. out must be an array of at least size pentagonIndexCount().

pentagonIndexCount

int pentagonIndexCount(void);

Number of pentagon H3 indexes per resolution. This is always 12, but provided as a convenience.

pointDistKm

double pointDistKm(const GeoCoord *a, const GeoCoord *b);

Gives the "great circle" or "haversine" distance between pairs of GeoCoord points (lat/lng pairs) in kilometers.

pointDistM

double pointDistM(const GeoCoord *a, const GeoCoord *b);

Gives the "great circle" or "haversine" distance between pairs of GeoCoord points (lat/lng pairs) in meters.

pointDistRads

double pointDistRads(const GeoCoord *a, const GeoCoord *b);

Gives the "great circle" or "haversine" distance between pairs of GeoCoord points (lat/lng pairs) in radians.