---
id: misc
title: Miscellaneous H3 functions
sidebar_label: Miscellaneous
slug: /api/misc
---

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

These functions include descriptions of the H3 grid system.

## degsToRads

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
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">

```js
h3.degsToRads(degrees)
```

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

</TabItem>
</Tabs>

Converts degrees to radians.

## radsToDegs

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
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">

```js
h3.radsToDegs(h)
```

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

</TabItem>
</Tabs>

Converts radians to degrees.

## getHexagonAreaAvgKm2

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error getHexagonAreaAvgKm2(int res, double *out);
```

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

```py
h3.get_hexagon_area_avg(res, unit='km^2')
```

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

```java
double getHexagonAreaAvg(int res, AreaUnit unit);
```

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

```js
h3.getHexagonAreaAvg(res, h3.UNITS.km2)
```

```js live
function example() {
  const res = 5;
  return h3.getHexagonAreaAvg(res, h3.UNITS.km2);
}
```

</TabItem>
</Tabs>

Average hexagon area in square kilometers at the given resolution. Excludes pentagons.

## getHexagonAreaAvgM2

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error getHexagonAreaAvgM2(int res, double *out);
```

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

```py
h3.get_hexagon_area_avg(res, unit='m^2')
```

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

```java
double getHexagonAreaAvg(int res, AreaUnit unit);
```

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

```js
h3.getHexagonAreaAvg(res, h3.UNITS.m2)
```

```js live
function example() {
  const res = 5;
  return h3.getHexagonAreaAvg(res, h3.UNITS.m2);
}
```

</TabItem>
</Tabs>

Average hexagon area in square meters at the given resolution. Excludes pentagons.



## cellAreaRads2

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error cellAreaRads2(H3Index h, double *out);
```

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

```py
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">

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

```js live
function example() {
  const h = '85283473fffffff';
  return h3.cellArea(h, h3.UNITS.rads2);
}
```

</TabItem>
</Tabs>

Exact area of specific cell in square radians.

## cellAreaKm2

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error cellAreaKm2(H3Index h, double *out);
```

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

```py
h3.cell_area(h, unit='km^2')
```

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

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

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

```js
h3.cellArea(h, h3.UNITS.km2)
```

```js live
function example() {
  const h = '85283473fffffff';
  return h3.cellArea(h, h3.UNITS.km2);
}
```

</TabItem>
</Tabs>

Exact area of specific cell in square kilometers.

## cellAreaM2

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error cellAreaM2(H3Index h, double *out);
```

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

```py
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">

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

```js live
function example() {
  const h = '85283473fffffff';
  return h3.cellArea(h, h3.UNITS.m2);
}
```

</TabItem>
</Tabs>

Exact area of specific cell in square meters.

## getHexagonEdgeLengthAvgKm

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error getHexagonEdgeLengthAvgKm(int res, double *out);
```

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

```py
h3.get_hexagon_edge_length_avg(res, unit='km')
```

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

```java
double getHexagonEdgeLengthAvg(int res, LengthUnit unit);
```

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

```js
h3.getHexagonEdgeLengthAvg(res, h3.UNITS.km)
```

```js live
function example() {
  const res = 5;
  return h3.getHexagonEdgeLengthAvg(res, h3.UNITS.km);
}
```

</TabItem>
</Tabs>

Average hexagon edge length in kilometers at the given resolution. Excludes pentagons.

## getHexagonEdgeLengthAvgM

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error getHexagonEdgeLengthAvgM(int res, double *out);
```

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

```py
h3.get_hexagon_edge_length_avg(res, unit='m')
```

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

```java
double getHexagonEdgeLengthAvg(int res, LengthUnit unit);
```

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

```js
h3.getHexagonEdgeLengthAvg(res, h3.UNITS.m)
```

```js live
function example() {
  const res = 5;
  return h3.getHexagonEdgeLengthAvg(res, h3.UNITS.m);
}
```

</TabItem>
</Tabs>

Average hexagon edge length in meters at the given resolution. Excludes pentagons.


## edgeLengthKm

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error edgeLengthKm(H3Index edge, double *length);
```

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

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

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

```java
double edgeLength(long h3, LengthUnit unit);
double edgeLength(String h3Address, LengthUnit unit);
```

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

```js
h3.edgeLength(h3, h3.UNITS.km)
```

```js live
function example() {
  const h = '115283473fffffff';
  return h3.edgeLength(h, h3.UNITS.km);
}
```

</TabItem>
</Tabs>

Exact edge length of specific unidirectional edge in kilometers.

## edgeLengthM

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error edgeLengthM(H3Index edge, double *length);
```

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

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

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

```java
double edgeLength(long h3, LengthUnit unit);
double edgeLength(String h3Address, LengthUnit unit);
```

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

```js
h3.edgeLength(h3, h3.UNITS.m)
```

```js live
function example() {
  const h = '115283473fffffff';
  return h3.edgeLength(h, h3.UNITS.m);
}
```

</TabItem>
</Tabs>

Exact edge length of specific unidirectional edge in meters.

## edgeLengthRads

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error edgeLengthRads(H3Index edge, double *length);
```

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

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

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

```java
double edgeLength(long h3, LengthUnit unit);
double edgeLength(String h3Address, LengthUnit unit);
```

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

```js
h3.edgeLength(h3, h3.UNITS.rads)
```

```js live
function example() {
  const h = '115283473fffffff';
  return h3.edgeLength(h, h3.UNITS.rads);
}
```

</TabItem>
</Tabs>

Exact edge length of specific unidirectional edge in radians.

## getNumCells

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error getNumCells(int res, int64_t *out);
```

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

```py
h3.get_num_cells(res)
```

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

```java
long getNumCells(int res);
```

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

```js
h3.getNumCells(res)
```

```js live
function example() {
  const res = 5;
  return h3.getNumCells(res);
}
```

</TabItem>
</Tabs>

Number of unique H3 indexes at the given resolution.

## getRes0Cells

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error getRes0Cells(H3Index *out);
```

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

```py
h3.get_res0_cells(res)
```

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

```java
Collection<Long> getRes0Cells(int res);
Collection<String> getRes0CellsAddresses(int res);
```

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

```js
h3.getRes0Cells(res)
```

```js live
function example() {
  const res = 5;
  return h3.getRes0Cells(res);
}
```

</TabItem>
</Tabs>

All the resolution 0 H3 indexes.
`out` must be an array of at least size `res0CellCount()`.

## res0CellCount

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
int res0CellCount();
```

</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, which is defined as 122.

## getPentagons

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
H3Error getPentagons(int res, H3Index *out);
```

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

```py
h3.get_pentagons(res)
```

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

```java
Collection<Long> h3.getPentagons(int res);
Collection<String> h3.getPentagonsAddresses(int res);
```

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

```js
h3.getPentagons(res)
```

```js live
function example() {
  const res = 5;
  return h3.getPentagons(res);
}
```

</TabItem>
</Tabs>

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

Returns 0 (`E_SUCCESS`) on success.

## pentagonCount

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
int pentagonCount();
```

</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.

## greatCircleDistanceKm

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
double greatCircleDistanceKm(const LatLng *a, const LatLng *b);
```

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

```py
h3.great_circle_distance(point1, point2, unit='km')
```

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

```java
double greatCircleDistance(LatLng point1, LatLng point2, LengthUnit unit);
```

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

```js
h3.greatCircleDistance(point1, point2, h3.UNITS.km)
```

```js live
function example() {
  const point1 = [-10, 0];
  const point2 = [10, 0];
  return h3.greatCircleDistance(point1, point2, h3.UNITS.km)
}
```

</TabItem>
</Tabs>

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

## greatCircleDistanceM

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
double greatCircleDistanceM(const LatLng *a, const LatLng *b);
```

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

```py
h3.latlng_distance(point1, point2, unit='m')
```

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

```java
double greatCircleDistance(LatLng point1, LatLng point2, LengthUnit unit);
```

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

```js
h3.greatCircleDistance(point1, point2, h3.UNITS.m);
```

```js live
function example() {
  const point1 = [-10, 0];
  const point2 = [10, 0];
  return h3.greatCircleDistance(point1, point2, h3.UNITS.m);
}
```

</TabItem>
</Tabs>

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

## greatCircleDistanceRads

<Tabs
  groupId="language"
  defaultValue="c"
  values={[
    {label: 'C', value: 'c'},
    {label: 'Python', value: 'python'},
    {label: 'Java', value: 'java'},
    {label: 'JavaScript (Live)', value: 'javascript'},
  ]
}>
<TabItem value="c">

```c
double greatCircleDistanceRads(const LatLng *a, const LatLng *b);
```

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

```py
h3.latlng_distance(point1, point2, unit='rads')
```

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

```java
double greatCircleDistance(LatLng point1, LatLng point2, LengthUnit unit);
```

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

```js
h3.greatCircleDistance(point1, point2, h3.UNITS.rads)
```

```js live
function example() {
  const point1 = [-10, 0];
  const point2 = [10, 0];
  return h3.greatCircleDistance(point1, point2, h3.UNITS.rads)
}
```

</TabItem>
</Tabs>

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