Miscellaneous H3 functions - H3

import Tabs from '@theme/Tabs'; import TabItem from '@theme/TabItem';

These functions include descriptions of the H3 grid system.

degsToRads

double degsToRads(double degrees);

</TabItem> <TabItem value="python">

:::note

Use math.radians(degrees) instead.

:::

</TabItem> <TabItem value="java">

:::note

Use java.lang.Math.toRadians(double degrees) instead.

:::

</TabItem> <TabItem value="javascript">

h3.degsToRads(degrees)

function example() {
  const degrees = 45;
  return h3.degsToRads(degrees);
}

</TabItem> </Tabs>

Converts degrees to radians.

radsToDegs

double radsToDegs(double radians);

</TabItem> <TabItem value="python">

:::note

Use math.degrees(radians) instead.

:::

</TabItem> <TabItem value="java">

:::note

Use java.lang.Math.toDegrees(double radians) instead.

:::

</TabItem> <TabItem value="javascript">

h3.radsToDegs(h)

function example() {
  const radians = 3.14159;
  return h3.radsToDegs(radians);
}

</TabItem> </Tabs>

Converts radians to degrees.

hexAreaKm2

double hexAreaKm2(int res);

</TabItem> <TabItem value="python">

h3.hex_area(res, unit='km^2')

</TabItem> <TabItem value="java">

java

double hexArea(int res, AreaUnit unit);

</TabItem> <TabItem value="javascript">

h3.hexArea(res, h3.UNITS.km2)

function example() {
  const res = 5;
  return h3v3.hexArea(res, h3v3.UNITS.km2);
}

</TabItem> </Tabs>

Average hexagon area in square kilometers at the given resolution.

hexAreaM2

double hexAreaM2(int res);

</TabItem> <TabItem value="python">

h3.hex_area(res, unit='m^2')

</TabItem> <TabItem value="java">

java

double hexArea(int res, AreaUnit unit);

</TabItem> <TabItem value="javascript">

h3.hexArea(res, h3.UNITS.m2)

function example() {
  const res = 5;
  return h3v3.hexArea(res, h3v3.UNITS.m2);
}

</TabItem> </Tabs>

Average hexagon area in square meters at the given resolution.

cellAreaM2

double cellAreaM2(H3Index h);

</TabItem> <TabItem value="python">

h3.cell_area(h, unit='m^2')

</TabItem> <TabItem value="java">

java

double cellArea(long h3, AreaUnit unit);
int cellArea(String h3Address, AreaUnit unit);

</TabItem> <TabItem value="javascript">

h3.cellArea(h, h3.UNITS.m2)

function example() {
  const h = '85283473fffffff';
  return h3v3.cellArea(h, h3v3.UNITS.m2);
}

</TabItem> </Tabs>

Exact area of specific cell in square meters.

cellAreaRads2

double cellAreaRads2(H3Index h);

</TabItem> <TabItem value="python">

h3.cell_area(h, unit='rads^2')

</TabItem> <TabItem value="java">

java

double cellArea(long h3, AreaUnit unit);
int cellArea(String h3Address, AreaUnit unit);

</TabItem> <TabItem value="javascript">

h3.cellArea(h, h3.UNITS.rads2)

function example() {
  const h = '85283473fffffff';
  return h3v3.cellArea(h, h3v3.UNITS.rads2);
}

</TabItem> </Tabs>

Exact area of specific cell in square radians.

edgeLengthKm

double edgeLengthKm(int res);

</TabItem> <TabItem value="python">

h3.edge_length(res, unit='km')

</TabItem> <TabItem value="java">

java

double edgeLength(int res, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.edgeLength(res, h3.UNITS.km)

function example() {
  const res = 5;
  return h3v3.edgeLength(res, h3v3.UNITS.km);
}

</TabItem> </Tabs>

Average hexagon edge length in kilometers at the given resolution.

edgeLengthM

double edgeLengthM(int res);

</TabItem> <TabItem value="python">

h3.edge_length(res, unit='m')

</TabItem> <TabItem value="java">

java

double edgeLength(int res, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.edgeLength(res, h3.UNITS.m)

function example() {
  const res = 5;
  return h3v3.edgeLength(res, h3v3.UNITS.m);
}

</TabItem> </Tabs>

Average hexagon edge length in meters at the given resolution.

exactEdgeLengthKm

double exactEdgeLengthKm(H3Index edge);

</TabItem> <TabItem value="python">

h3.exact_edge_length(h, unit='km')

</TabItem> <TabItem value="java">

java

double exactEdgeLength(long h3, LengthUnit unit);
double exactEdgeLength(String h3Address, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.exactEdgeLength(h3, h3.UNITS.km)

function example() {
  const h = '115283473fffffff';
  return h3v3.exactEdgeLength(h, h3v3.UNITS.km);
}

</TabItem> </Tabs>

Exact edge length of specific unidirectional edge in kilometers.

exactEdgeLengthM

double exactEdgeLengthM(H3Index edge);

</TabItem> <TabItem value="python">

h3.exact_edge_length(h, unit='m')

</TabItem> <TabItem value="java">

java

double exactEdgeLength(long h3, LengthUnit unit);
double exactEdgeLength(String h3Address, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.exactEdgeLength(h3, h3.UNITS.m)

function example() {
  const h = '115283473fffffff';
  return h3v3.exactEdgeLength(h, h3v3.UNITS.m);
}

</TabItem> </Tabs>

Exact edge length of specific unidirectional edge in meters.

exactEdgeLengthRads

double exactEdgeLengthRads(H3Index edge);

</TabItem> <TabItem value="python">

h3.exact_edge_length(h, unit='rads')

</TabItem> <TabItem value="java">

java

double exactEdgeLength(long h3, LengthUnit unit);
double exactEdgeLength(String h3Address, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.exactEdgeLength(h3, h3.UNITS.rads)

function example() {
  const h = '115283473fffffff';
  return h3v3.exactEdgeLength(h, h3v3.UNITS.rads);
}

</TabItem> </Tabs>

Exact edge length of specific unidirectional edge in radians.

numHexagons

int64_t numHexagons(int res);

</TabItem> <TabItem value="python">

h3.num_hexagons(res)

</TabItem> <TabItem value="java">

java

long numHexagons(int res);

</TabItem> <TabItem value="javascript">

h3.numHexagons(res)

function example() {
  const res = 5;
  return h3v3.numHexagons(res);
}

</TabItem> </Tabs>

Number of unique H3 indexes at the given resolution.

getRes0Indexes

void getRes0Indexes(H3Index *out);

</TabItem> <TabItem value="python">

h3.get_res0_indexes(res)

</TabItem> <TabItem value="java">

java

Collection<Long> getRes0Indexes(int res);
Collection<String> getRes0IndexesAddresses(int res);

</TabItem> <TabItem value="javascript">

h3.getRes0Indexes(res)

function example() {
  const res = 5;
  return h3v3.getRes0Indexes(res);
}

</TabItem> </Tabs>

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

res0IndexCount

int res0IndexCount(void);

</TabItem> <TabItem value="python">

:::note

This function exists for memory management and is not exposed.

:::

</TabItem> <TabItem value="java">

:::note

This function exists for memory management and is not exposed.

:::

</TabItem> <TabItem value="javascript">

:::note

This function exists for memory management and is not exposed.

:::

</TabItem> </Tabs>

Number of resolution 0 H3 indexes.

getPentagonIndexes

void getPentagonIndexes(int res, H3Index *out);

</TabItem> <TabItem value="python">

h3.get_pentagon_indexes(res)

</TabItem> <TabItem value="java">

java

Collection<Long> getPentagonIndexes(int res);
Collection<String> getPentagonIndexesAddresses(int res);

</TabItem> <TabItem value="javascript">

h3.getPentagonIndexes(res)

function example() {
  const res = 5;
  return h3v3.getPentagonIndexes(res);
}

</TabItem> </Tabs>

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

pentagonIndexCount

int pentagonIndexCount(void);

</TabItem> <TabItem value="python">

:::note

This function exists for memory management and is not exposed.

:::

</TabItem> <TabItem value="java">

:::note

This function exists for memory management and is not exposed.

:::

</TabItem> <TabItem value="javascript">

:::note

This function exists for memory management and is not exposed.

:::

</TabItem> </Tabs>

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);

</TabItem> <TabItem value="python">

h3.point_dist(point1, point2, unit='km')

</TabItem> <TabItem value="java">

java

double pointDist(GeoCoord point1, GeoCoord point2, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.pointDist(point1, point2, h3.UNITS.km)

function example() {
  const point1 = [-10, 0];
  const point2 = [10, 0];
  return h3v3.pointDist(point1, point2, h3v3.UNITS.km)
}

</TabItem> </Tabs>

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);

</TabItem> <TabItem value="python">

h3.point_dist(point1, point2, unit='m')

</TabItem> <TabItem value="java">

java

double pointDist(GeoCoord point1, GeoCoord point2, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.pointDist(point1, point2, h3.UNITS.m)

function example() {
  const point1 = [-10, 0];
  const point2 = [10, 0];
  return h3v3.pointDist(point1, point2, h3v3.UNITS.m)
}

</TabItem> </Tabs>

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);

</TabItem> <TabItem value="python">

h3.point_dist(point1, point2, unit='rads')

</TabItem> <TabItem value="java">

java

double pointDist(GeoCoord point1, GeoCoord point2, LengthUnit unit);

</TabItem> <TabItem value="javascript">

h3.pointDist(point1, point2, h3.UNITS.rads)

function example() {
  const point1 = [-10, 0];
  const point2 = [10, 0];
  return h3v3.pointDist(point1, point2, h3v3.UNITS.rads)
}

</TabItem> </Tabs>

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