rclark’s gists

rclark / action.py

Created July 16, 2013 20:45

Layer generation action

	def publish(context, data_dict):
	# Gather inputs
	resource_id = data_dict.get("resource_id", None)
	layer_name = data_dict.get("layer_name", resource_id)
	username = context.get("user", None)
	package_id = data_dict.get("package_id", None)
	lat_field = data_dict.get("col_latitude", None)
	lng_field = data_dict.get("col_longitude", None)

	# Check that you have everything you need

rclark / test_some_actions.py

Created July 17, 2013 23:57

Little action testing example

	from ckanext.ngds.tests.ngds_test_case import NgdsTestCase

	class MyActionTestCase(NgdsTestCase):

	def test_gobbledee_action(self):
	# Generate your POST body
	post_body = {
	"turkeys": 12,
	"gobbles": ["gobble", "gobble"]
	}

rclark / failed-polygonize.js

Created July 28, 2013 20:35

Example of jsts.operation.polygonize not working on arbitrary "spaghetti" lines

	var jsts = require("jsts"),
	spaghetti = [
	"LINESTRING(-108.6328125 32.54681317351517,-117.7734375 44.33956524809713,-91.0546875 50.51342652633956,-92.46093749999999 30.751277776257812)",
	"LINESTRING(-120.58593749999999 25.48295117535531,-106.5234375 42.032974332441405,-78.046875 40.713955826286046)"
	],
	reader = new jsts.io.WKTReader(),
	polygonizer = new jsts.operation.polygonize.Polygonizer(),
	polygons, dangles, cutEdges, invalidRingLines;

	spaghetti.forEach(function (line) {

rclark / lines2polysUnion.js

Last active June 10, 2017 12:34

JSTS to create polygons from spaghetti lines. Union on lines is the "planarize" step, and is extremely time-consuming for larg-ish numbers of lines (~300 it takes about 2 seconds per each new line to union).

	var jsts = require("jsts"),
	_ = require("underscore"),
	fs = require("fs");

	fs.readFile("/Users/ryan/Desktop/hv-lines.geojson", function (err, data) {
	var geojson = JSON.parse(data),
	reader = new jsts.io.GeoJSONReader(),
	writer = new jsts.io.GeoJSONWriter(),
	polygonizer = new jsts.operation.polygonize.Polygonizer(),

rclark / error.log

Created July 31, 2013 17:23

Error running TileMill 2 on OSX

	WeeSofty:tm2 ryan$ brew upgrade mapnik
	Error: mapnik-2.2.0 already installed
	WeeSofty:tm2 ryan$ brew upgrade protobuf
	Error: protobuf-2.5.0 already installed
	WeeSofty:tm2 ryan$ brew upgrade node
	Error: node-0.10.15 already installed
	WeeSofty:tm2 ryan$ node index.js

	module.js:356
	Module._extensions[extension](this, filename);

rclark / parse-fema.js

Created August 1, 2013 00:32

Trying to mine data from FEMA National Flood Hazard Layer

	var fs = require("fs"),
	_ = require("underscore"),
	request = require("request"),
	baseUrl = "https://hazards.fema.gov/gis/nfhl/rest/services/public/NFHL/MapServer/28",
	outEsri = JSON.stringify({"displayFieldName":"DFIRM_ID","fieldAliases":{"FLD_ZONE":"FLD_ZONE","ZONE_SUBTY":"ZONE_SUBTY"},"fields":[{"name":"FLD_ZONE","type":"esriFieldTypeString","alias":"FLD_ZONE","length":17},{"name":"ZONE_SUBTY","type":"esriFieldTypeString","alias":"ZONE_SUBTY","length":57}]}),
	outFile = fs.createWriteStream("fema-get-all-esri.json");

	outFile.write(outEsri + ",features:[");

	request(baseUrl + "?f=json", function (err, response, information) {

rclark / lines2polysNoder.js

Created August 6, 2013 21:34

JSTS to create polygons from a network of arbitrary, or "spaghetti" lines. This uses jsts.noding to "clean" or "planarize" the line network, which is crazy fast compared to the "Union" alternative here: https://gist.github.com/rclark/6123614

	var jsts = require("jsts"),
	u = require("underscore"),
	fs = require("fs");

	fs.readFile("/Users/ryan/Desktop/hv-lines.geojson", function (err, data) {
	var geojson = JSON.parse(data),
	writer = new jsts.io.GeoJSONWriter(),
	polygonizer = new jsts.operation.polygonize.Polygonizer(),
	noder = new jsts.noding.MCIndexNoder(),
	intersector = new jsts.algorithm.RobustLineIntersector(),

rclark / index.html

Created August 6, 2013 22:20

via:geojson.io


	<!DOCTYPE html>
	<html>
	<head>
	<meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
	<style>
	body { margin:0; padding:0; }
	#map { position:absolute; top:0; bottom:0; width:100%; }
	.marker-properties {
	border-collapse:collapse;

rclark / testNoder.js

Last active March 11, 2018 19:41

Example of "cleaning" a line network using JSTS to create a properly noded segment network (i.e. nodes at every intersection between segments).

	var jsts = require("jsts"),
	fs = require("fs"),
	javascript = require("javascript.util"),
	assert = require("assert"),
	lines = [
	"LINESTRING(-110.5 32.1,-110.45 32.2,-110.4 32.1)",
	"LINESTRING(-110.5 32.25,-110.45 32.2,-110.45 32.15,-110.4 32.25)"
	],
	expected = [
	"LINESTRING(-110.5 32.1,-110.45 32.2)",

rclark / countries.geojson

Created August 15, 2013 21:37

Countries

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Ryan Clark rclark