Nick Rabinowitz nrabinowitz

id	LastSeen_A	hex7	Lat	Lon	PM2_5Value_A	AirQualityIndex	AirQualityIndex_Description
95	2020-11-07 00:00	871259724ffffff	52.11083221435547	-106.66564178466797	33.879999999999995	96.5	Moderate
130	2020-11-07 00:00	8712c0702ffffff	51.29340744018555	-116.96610260009766	12.18	51	Moderate
131	2020-11-07 00:00	8712c1014ffffff	51.090633392333984	-115.33135223388672	3.86	16	Good
132	2020-11-07 00:00	8712c1016ffffff	51.08929443359375	-115.34068298339844	2.58	11	Good
133	2020-11-07 00:00	8712c1b2bffffff	51.32834243774414	-114.59577178955078	10.09	42	Good
134	2020-11-07 00:00	8712c2185ffffff	51.00360870361328	-118.210693359375	2	8	Good
135	2020-11-07 00:00	8712c8295ffffff	49.199100494384766	-113.3031005859375	7.75	32	Good
136	2020-11-07 00:00	8712ca099ffffff	48.85100173950195	-114.93699645996094	4.42	18	Good
137	2020-11-07 00:00	8712cb598ffffff	48.443748474121094	-114.10562133789062	0.22	1	Good

Images and data for H3 tutorials

This demonstrates raster-based reverse geocoding using canvas and D3.js. Geocoding is based on the color of the pixel at a given projected position. Note that the canvas is only shown here for the sake of explanation and debugging - this would in fact probably work faster if the canvas was not attached to the document at all.

The biggest remaining issue here is precision, which depends on:

the size of the canvas, and
the projection used.

Determining the optimum size based on the accuracy of your data is left as an exercise for the reader. Edge cases will also fail here, generally returning null - one option might be to stroke neighborhoods in a color, and then return an "uncertain" value for any non-grayscale pixel.

	{
	UNITS: h3v4.UNITS,
	h3IndexToSplitLong: h3v4.h3IndexToSplitLong,
	splitLongToH3Index: h3v4.splitLongToH3Index,
	h3IsValid: h3v4.isValidCell,
	h3IsPentagon: h3v4.isPentagon,
	h3IsResClassIII: h3v4.isResClassIII,
	h3GetBaseCell: h3v4.getBaseCellNumber,
	h3GetFaces: h3v4.getIcosahedronFaces,
	h3GetResolution: h3v4.getResolution,

	{
	"type": "MultiLineString",
	"coordinates": [
	[
	[-176.51528829392126, 56.22382026488319],
	[-177.666887558162, 56.2558355327094],
	[-178.82009217995488, 56.27714350189036],
	[-179.97425867250774, 56.287723610665964],
	[-180, 56.28772008819492],
	[-179.97425867250772, 56.287723610665964],

	c_cyan=`tput setaf 6`
	c_red=`tput setaf 1`
	c_green=`tput setaf 2`
	c_sgr0=`tput sgr0`

	parse_git_branch ()
	{
	if git rev-parse --git-dir >/dev/null 2>&1
	then
	gitver="[$(git branch 2>/dev/null\| sed -n '/^\/s/^\ //p')]"

	<!DOCTYPE html>
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
	<title>One Graph</title>
	<script type="text/javascript" src="http://mbostock.github.com/d3/d3.v2.js"></script>
	<script type="text/javascript" src="simple-graph.js"></script>
	<style type="text/css">
	body { font: 13px sans-serif; }
	rect { fill: #fff; }