GIS - Uber H3 In React: A Comprehensive Guide

H3 is a hexagonal hierarchical geospatial indexing system developed by Uber. It is designed to efficiently represent and manipulate geospatial data at different levels of detail. H3-js is a JavaScript library that provides a convenient way to use H3 in React applications. In this comprehensive guide, we will explore the features of H3-js and provide detailed code examples to help you get started.

Getting Started

To use H3-js in your React application, you will need to install it using npm:

npm install h3-js

Once you have installed H3-js, you can import it into your React component like this:

import * as h3 from 'h3-js';

Basic Usage

The most basic operation you can perform with H3 is to convert a latitude and longitude coordinate to an H3 index. You can do this using the h3.geoToH3 function:

const h3Index = h3.geoToH3(latitude, longitude, resolution);

Here, latitude and longitude are the coordinates of the point you want to convert, and resolution is the desired resolution of the H3 index. The resolution can range from 0 to 15, with higher resolutions resulting in more detailed indexes.

H3 Hexagons

H3 indexes represent hexagons on the globe. You can use the h3.h3ToGeoBoundary function to get the geographic boundary of an H3 hexagon:

const boundary = h3.h3ToGeoBoundary(h3Index);

The boundary will be an array of latitude and longitude coordinates that define the boundary of the hexagon.

H3 Neighbors

H3 hexagons can be adjacent to each other in different directions. You can use the h3.h3GetNeighbors function to get the H3 indexes of the neighbors of a given hexagon:

const neighbors = h3.h3GetNeighbors(h3Index);

The neighbors will be an array of H3 indexes that represent the neighbors of the given hexagon.

Advanced Usage

In addition to the basic operations described above, H3-js also provides a number of advanced features, such as:

• Distance Calculations: You can use H3-js to calculate the distance between two H3 hexagons.
• Area Calculations: You can use H3-js to calculate the area of an H3 hexagon.
• Spatial Queries: You can use H3-js to perform spatial queries, such as finding all the H3 hexagons that intersect with a given boundary.

Code Examples

Here are some code examples to demonstrate how to use H3-js in React applications:

Example 1: Converting Coordinates to H3 Index

import * as h3 from 'h3-js';


const MyComponent = () => {
  const latitude = 37.7749;
  const longitude = -122.4194;
  const h3Index = h3.geoToH3(latitude, longitude, 8);


  return (
    <div>
      H3 Index: {h3Index}
    </div>
  );
};


export default MyComponent;

Example 2: Getting H3 Hexagon Boundary

import * as h3 from 'h3-js';


const MyComponent = () => {
  const h3Index = '8b3da102cb72fff';
  const boundary = h3.h3ToGeoBoundary(h3Index);


  return (
    <div>
      H3 Hexagon Boundary: {boundary}
    </div>
  );
};


export default MyComponent;

Example 3: Finding H3 Neighbors

import * as h3 from 'h3-js';


const MyComponent = () => {
  const h3Index = '8b3da102cb72fff';
  const neighbors = h3.h3GetNeighbors(h3Index);


  return (
    <div>
      H3 Neighbors: {neighbors}
    </div>
  );
};


export default MyComponent;

Additional Content:

The following github project makes use of uber h3 with leaflet built on react js.

https://github.com/808vita/maps-with-uber-h3

This github repositry can provide you ideas on how uber h3 is implemented together with other libraries like leaflet js, leaflet routing machine ,etc to make feature rich GIS web applications for end users.

Conclusion

H3-js is a powerful library that makes it easy to use H3 in React applications. In this comprehensive guide, we have explored the features of H3-js and provided detailed code examples to help you get started. By following the steps outlined in this guide, you can use H3-js to improve the geospatial capabilities of your React applications.