Table of Contents

Index inspection functions

These functions provide metadata about an H3 index, such as its resolution or base cell, and provide utilities for converting into and out of the 64-bit representation of an H3 index.

h3GetResolution

int h3GetResolution(H3Index h);

Returns the resolution of the index.

h3GetBaseCell

int h3GetBaseCell(H3Index h);

Returns the base cell number of the index.

stringToH3

H3Index stringToH3(const char *str);

Converts the string representation to H3Index (uint64_t) representation.

Returns 0 on error.

h3ToString

void h3ToString(H3Index h, char *str, size_t sz);

Converts the H3Index representation of the index to the string representation. str must be at least of length 17.

h3IsValid

int h3IsValid(H3Index h);

Returns non-zero if this is a valid H3 index.

h3IsResClassIII

int h3IsResClassIII(H3Index h);

Returns non-zero if this index has a resolution with Class III orientation.

h3IsPentagon

int h3IsPentagon(H3Index h);

Returns non-zero if this index represents a pentagonal cell.

h3GetFaces

void h3GetFaces(H3Index h, int* out);

Find all icosahedron faces intersected by a given H3 index and places them in the array out. out must be at least of length maxFaceCount(h).

Faces are represented as integers from 0-19, inclusive. The array is sparse, and empty (no intersection) array values are represented by -1.

maxFaceCount

int maxFaceCount(H3Index h3);

Returns the maximum number of icosahedron faces the given H3 index may intersect.