Hierarchical grid functions
These functions permit moving between resolutions in the H3 grid system. The functions produce parent (coarser) or children (finer) cells.
h3ToParent
- C
- Python
- Java
- JavaScript (Live)
H3Index h3ToParent(H3Index h, int parentRes);
h3.h3_to_parent(h, parent_res)
long h3ToParent(long h3, int parentRes);
String h3ToParent(String h3Address, int parentRes);
h3.h3ToParent(h3Index, parentRes)
Returns the parent (coarser) index containing h
.
h3ToChildren
- C
- Python
- Java
- JavaScript (Live)
void h3ToChildren(H3Index h, int childRes, H3Index *children);
h3.h3_to_children(h, child_res)
List<Long> h3ToChildren(long h3, int childRes);
List<String> h3ToChildren(String h3Address, int childRes);
h3.h3ToChildren(h3Index, childRes)
Populates children
with the indexes contained by h
at resolution childRes
. children
must be an array of at least size maxH3ToChildrenSize(h, childRes)
.
maxH3ToChildrenSize
- C
- Python
- Java
- JavaScript (Live)
int maxH3ToChildrenSize(H3Index h, int childRes);
This function exists for memory management and is not exposed.
This function exists for memory management and is not exposed.
This function exists for memory management and is not exposed.
Returns the parent (coarser) index containing h
.
h3ToCenterChild
- C
- Python
- Java
- JavaScript (Live)
H3Index h3ToCenterChild(H3Index h, int childRes);
h3.h3_to_center_child(h3, child_res)
long h3ToCenterChild(long h3, int childRes);
String h3ToCenterChild(String h3, int childRes);
h3.h3ToCenterChild(h, childRes)
Returns the center child (finer) index contained by h
at resolution childRes
.
compact
- C
- Python
- Java
- JavaScript (Live)
int compact(const H3Index *h3Set, H3Index *compactedSet, const int numHexes);
h3.compact(hexes)
List<Long> compact(Collection<Long> h3);
List<String> compactAddress(Collection<String> h3);
h3.compact(hexes)
Compacts the set h3Set
of indexes as best as possible, into the array compactedSet
. compactedSet
must be at least the size of h3Set
in case the set cannot be compacted.
Returns 0 on success.
uncompact
- C
- Python
- Java
- JavaScript (Live)
int uncompact(const H3Index *compactedSet, const int numHexes, H3Index *h3Set, const int maxHexes, const int res);
h3.uncompact(hexes, res)
List<Long> uncompact(Collection<Long> h3, int res);
List<String> uncompactAddress(Collection<String> h3, int res);
h3.uncompact(hexes, res)
Uncompacts the set compactedSet
of indexes to the resolution res
. h3Set
must be at least of size maxUncompactSize(compactedSet, numHexes, res)
.
Returns 0 on success.
maxUncompactSize
- C
- Python
- Java
- JavaScript (Live)
int maxUncompactSize(const H3Index *compactedSet, const int numHexes, const int res)
This function exists for memory management and is not exposed.
This function exists for memory management and is not exposed.
This function exists for memory management and is not exposed.
Returns the size of the array needed by uncompact
.