2d:null 2e:["$","title",null,{"children":"How many Jacaranda trees are there in Sydney? | Leo Orpilla III | Observable"}] 33:T73f,mapCluster = { if (showMap) { const container = yield htl.html`

`; const map = L.map(container).setView([-33.89, 151.21], 13); L.tileLayer( "https://tiles.stadiamaps.com/tiles/alidade_smooth/{z}/{x}/{y}{r}.{ext}", { minZoom: 0, maxZoom: 20, attribution: '© Stadia Maps © OpenMapTiles © OpenStreetMap contributors', ext: "png" } ).addTo(map); L.geoJson(sydney_lga, { style: { color: "black", fill: false, weight: 1 } }).addTo(map); const layer = L.layerGroup().addTo(map); const trees = Object.values(jacarandaDataWithClusters).forEach((tree) => { const marker = L.circle( { lat: tree.lat, lng: tree.lng }, { color: turbo[tree.cluster] } ).addTo(layer); marker.bindPopup( `Species: ${tree.SpeciesName}
Type: ${tree.TreeType}
Height: ${tree.TreeHeight}m` ); }); } else { yield Plot.plot({ marginLeft: 50, aspectRatio: 1, marks: [ Plot.geo(sydney_lga), Plot.dot(jacarandaData, { x: "lng", y: "lat", fill: (_, i) => Object.hasOwn(jacarandaDataWithClusters, i) ? turbo[jacarandaDataWithClusters[i].cluster] : "gray", opacity: (_, i) => Object.hasOwn(jacarandaDataWithClusters, i) ? 1 : 0.6 }), Plot.hull(Object.values(jacarandaDataWithClusters), { x: "lng", y: "lat", z: "cluster", fill: (d) => turbo[d.cluster], fillOpacity: 0.2 }) ] }); } }34:[{"id":"159aab6388d694dcf87d9473fe7a2dd14011bbd10fdcad65dc99502d0c39f9478d0d754cfbf1c7830a8f1ec403a88e5f206902a80b9f45b09d812162e89ae329","href":"https://static.observableusercontent.com/files/159aab6388d694dcf87d9473fe7a2dd14011bbd10fdcad65dc99502d0c39f9478d0d754cfbf1c7830a8f1ec403a88e5f206902a80b9f45b09d812162e89ae329","name":"sydney_trees.csv","type":"text/csv","lastModified":1700385993407.673,"size":4483666},{"id":"ad1c21673c6051b073f718ca1099d5e7506164771f4ac2d84476afa88438488508f904d7f0f050fbe2232c096d77393219d89bb10406375a4cec154b89f9abdc","href":"https://static.observableusercontent.com/files/ad1c21673c6051b073f718ca1099d5e7506164771f4ac2d84476afa88438488508f904d7f0f050fbe2232c096d77393219d89bb10406375a4cec154b89f9abdc","name":"mitchell-luo-8I1XZYwK_Gc-unsplash-2.jpg","type":"image/jpeg","lastModified":1700388104827.583,"size":1296579},{"id":"b864c8a0bd61f500199293e6689439a59b1e58b50fb8c6d01aff58a0e1cfc0ceb9949e0a42b58caa914638713afa3f567192b9bc9a2df5e526445e39924828c4","href":"https://static.observableusercontent.com/files/b864c8a0bd61f500199293e6689439a59b1e58b50fb8c6d01aff58a0e1cfc0ceb9949e0a42b58caa914638713afa3f567192b9bc9a2df5e526445e39924828c4","name":"The_City_of_Sydney_Local_Government_Area.geojson","type":"application/geo+json","lastModified":1700393202064.042,"size":195185}] 31:{"id":"e07d964ab3d48d54","slug":"sydney-trees-jacaranda","title":"How many Jacaranda trees are there in Sydney?","thumbnail":"979f4cbbb14dd512858373bb0c14dc04480b41a7a7e4a3e2c97a01d0c9800112","access_level":"public","create_time":"$D2023-11-19T09:24:51.843Z","update_time":"$D2023-11-21T03:04:56.025Z","view_time":null,"first_public_time":"$D2023-11-19T12:43:06.048Z","fork":false,"stars":2,"starred":false,"owner":{"type":"team","id":"304df413ac6d9b3b","login":"ldgrp","name":"Leo Orpilla III","avatar_url":"https://avatars-next.observableusercontent.com/9743f8415274ff1b872aff405e8a77d6dd9c25f412b1ce8853f1dee939c67e9a","tier":"starter_2024"},"version":1185,"publish_version":null,"role":null,"authored":false,"authors":[{"type":"individual","id":"4d2ca89f2665bbeb","login":"ldgrp","name":"Leo Orpilla III","avatar_url":"https://avatars-next.observableusercontent.com/9743f8415274ff1b872aff405e8a77d6dd9c25f412b1ce8853f1dee939c67e9a","tier":null}],"members":[{"type":"individual","id":"4d2ca89f2665bbeb","login":"ldgrp","name":"Leo Orpilla III","avatar_url":"https://avatars-next.observableusercontent.com/9743f8415274ff1b872aff405e8a77d6dd9c25f412b1ce8853f1dee939c67e9a","tier":null,"role":"editor"}],"comments":[],"custom_thumbnail":false,"trashed":false,"lapsed":null,"subscribed":null,"forks":1,"collection":null,"type":"notebook","body":{"title":"How many Jacaranda trees are there in Sydney?","cells":[{"id":0,"value":"# How many Jacaranda trees are there in Sydney?\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":9,"value":"It's Jacaranda season! ","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":24,"value":"Starting in mid-October, the streets of Sydney begin to burst with a sea of purple as the Jacaranda trees show off their vibrant flowers until the end of spring. ","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":35,"value":"{\n const image = await FileAttachment(\n \"mitchell-luo-8I1XZYwK_Gc-unsplash-2.jpg\"\n ).image({ height: 500 });\n return html`${image}

Photo by Mitchell Luo on Unsplash

\n `;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":61,"value":"I've used the [City of Sydney's **Trees** dataset](https://data.cityofsydney.nsw.gov.au/datasets/cityofsydney::trees/about) to map out all the Jacaranda trees within the city. **Street Trees** are marked violet and **Park Trees** are marked purple.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":1182,"value":"There are **${jacarandaData.length}** Jacaranda trees in the City of Sydney.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":809,"value":"> ⚠️ You can tick the box below to show all trees. This will cause all **${treeData.length}** points to be drawn on Leaflet which might take a long time.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":294,"value":"viewof showAllTrees = Inputs.toggle({\n label: \"Show all trees\",\n value: false\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":64,"value":"map = {\n const container = yield htl.html`

`;\n const map = L.map(container).setView([-33.89, 151.21], 13);\n L.tileLayer(\n \"https://tiles.stadiamaps.com/tiles/alidade_smooth/{z}/{x}/{y}{r}.{ext}\",\n {\n minZoom: 0,\n maxZoom: 20,\n attribution:\n '© Stadia Maps © OpenMapTiles © OpenStreetMap contributors',\n ext: \"png\"\n }\n ).addTo(map);\n L.geoJson(sydney_lga, {\n style: {\n color: \"black\",\n fill: false,\n weight: 1\n }\n }).addTo(map);\n\n if (showAllTrees) treesLayer.addTo(map);\n\n jacarandaLayer.addTo(map);\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":96,"value":"jacarandaLayer = {\n const layer = L.layerGroup();\n const trees = treeData\n .filter(({ SpeciesName }) => SpeciesName === jacarandaSpeciesName)\n .forEach((tree) => {\n const marker = L.circle(\n { lat: tree.lat, lng: tree.lng },\n { color: tree.TreeType === \"Street Tree\" ? \"violet\" : \"purple\" }\n ).addTo(layer);\n marker.bindPopup(\n `Species: ${tree.SpeciesName}
Type: ${tree.TreeType}
Height: ${tree.TreeHeight}m`\n );\n });\n return layer;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":307,"value":"treesLayer = {\n const layer = L.layerGroup();\n const trees = treeData\n .filter(\n ({ SpeciesName }) => showAllTrees && SpeciesName !== jacarandaSpeciesName\n )\n .forEach((tree) => {\n const marker = L.circle(\n { lat: tree.lat, lng: tree.lng },\n { color: \"grey\", opacity: 0.2 }\n ).addTo(layer);\n marker.bindPopup(\n `Species: ${tree.SpeciesName}
Height: ${tree.TreeHeight}m`\n );\n });\n return layer;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":340,"value":"## Tree Diversity in Sydney","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":344,"value":"There are **${treeData.length}** reported trees in the City of Sydney. Among these, there are **${species.length}** unique species, highlighting the ecological variety that the city maintains.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":459,"value":"Plot.plot({\n marginLeft: 90,\n marginBottom: 40,\n marks: [\n Plot.barX(\n species,\n Plot.stackX({\n x: \"Count\",\n fill: \"SpeciesName\",\n tip: true\n })\n )\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":495,"value":"The Jacaranda is the **6th** most prevalent species in Sydney's urban canopy.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":403,"value":"Plot.plot({\n marginLeft: 80,\n marginBottom: 90,\n color: { legend: true },\n x: { tickRotate: -30, label: \"Species\" },\n marks: [\n Plot.barY(species.slice(0, 10), {\n x: \"SpeciesName\",\n y: \"Count\",\n sort: { x: \"y\", reverse: true },\n fill: (d) =>\n d.SpeciesName === jacarandaSpeciesName ? \"violet\" : \"black\",\n tip: true\n }),\n Plot.ruleY([0])\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":524,"value":"### Park Trees","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":527,"value":"Let's look at the distribution of **park** vs **street** trees in Sydney.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":529,"value":"Plot.plot({\n marginLeft: 90,\n color: { legend: true },\n marks: [\n Plot.barX(\n treeData,\n Plot.groupZ({ x: \"count\" }, { fill: \"TreeType\", tip: true })\n )\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":832,"value":"null","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":537,"value":"We can look at the individual species that make up each type","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":540,"value":"Plot.plot({\n marginLeft: 90,\n marginBottom: 50,\n marks: [\n Plot.barX(\n treeData,\n Plot.groupY(\n { x: \"count\" },\n {\n y: \"TreeType\",\n fill: (x) => x.SpeciesName,\n stroke: (x) =>\n x.SpeciesName === jacarandaSpeciesName ? \"black\" : \"transparent\",\n tip: true,\n order: \"sum\"\n }\n )\n )\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":852,"value":"### Tree Heights","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":846,"value":"Plot.plot({\n marks: [\n Plot.rectY(\n treeData,\n Plot.binX(\n { y2: \"count\", filter: null },\n {\n x: \"TreeHeight\",\n tip: true,\n thresholds: \"sturges\",\n fill: (x) =>\n x.SpeciesName === jacarandaSpeciesName ? \"violet\" : \"black\"\n }\n )\n ),\n Plot.ruleY([0])\n ]\n})","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":556,"value":"## Finding purple corridors","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":562,"value":"In this section, we'll use Density-Based Spatial Clustering of Applications with Noise (DBSCAN) to find streets or corridors in Sydney with a high density of Jacaranda trees.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":681,"value":"We are looking for clusters where there are at least **${minPoints}** trees. There are **${clusters.length}** such clusters. You can play around with the sliders below to change the parameters of the algorithm.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":635,"value":"jacarandaData = treeData.filter((t) => t.SpeciesName === jacarandaSpeciesName)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":576,"value":"viewof epsilon = Inputs.range([50, 500], {\n label: \"Epsilon\",\n step: 0.1,\n value: 150\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":578,"value":"viewof minPoints = Inputs.range([0, 10], {\n label: \"Min Points\",\n step: 1,\n value: 10\n})","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":583,"value":"dbscanner = {\n const dbscanner = jDBSCAN()\n .eps(epsilon)\n .minPts(minPoints)\n .data(jacarandaData);\n dbscanner();\n return dbscanner;\n}","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":587,"value":"clusters = dbscanner.getClusters()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":641,"value":"jacarandaDataWithClusters = Object.fromEntries(\n clusters.flatMap((cluster, clusterId) =>\n cluster.parts.map((i) => [i, { ...jacarandaData[i], cluster: clusterId }])\n )\n)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":764,"value":"The clusters are mapped below. The convex hull of the points are shown below to highlight each cluster. You can tick the box below to switch to map view.","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":917,"value":"viewof showMap = Inputs.toggle({ label: \"Show map\", value: false })","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":627,"value":"$33","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":911,"value":"### Hough Transform\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":818,"value":"> *Note*: *When I get the time, I'll look into implementing the [Hough Transform](https://en.wikipedia.org/wiki/Hough_transform) to find actual corridors (i.e. linear streets) instead of generic clusters of Jacaranda trees.*","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":338,"value":"---","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":127,"value":"### Appendix: EPSG7856\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":131,"value":"Leaflet comes with support for some common Coordinate Reference Systems (CRS) by default. These are\n\n1. **EPSG:3857**: Default. This is the most commonly used CRS for online maps. It uses a Spherical Mercator projection.\n2. **EPSG:4326**: Equirectangular projection.\n3. **EPSG:3395**: Elliptical Mercator projection\n4. **Simple**: Maps longitude and latitude into `x` and `y` directly.\n\nThe City of Sydney publishes spatial data in [EPSG:7856](https://epsg.io/7856). We need to transform these to a coordinate system that Leaflet understands.\n","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":151,"value":"proj4 = {\n const proj4 = await require(\"proj4@2.9.2/dist/proj4-src.js\");\n // Define EPSG:7856\n proj4.defs(\n \"EPSG:7856\",\n \"+proj=utm +zone=56 +south +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +type=crs\"\n );\n return proj4;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":149,"value":"proj4leaflet = require(\"proj4leaflet@1.0.2/src/proj4leaflet.js\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":168,"value":"crs = new proj4leaflet.CRS(\n \"EPSG:7856\",\n \"+proj=utm +zone=56 +south +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs +type=crs\"\n)","pinned":true,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":568,"value":"---","pinned":false,"hidden":false,"mode":"md","author":"$undefined","summary":"$undefined","output":"","database":"$undefined"},{"id":572,"value":"jDBSCAN = require(\"jdbscan@1.0.0/dist/jDBScan.js\")","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":100,"value":"client = {\n const client = await DuckDBClient.of({\n trees: FileAttachment(\"sydney_trees.csv\")\n });\n return client;\n}","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":276,"value":"sydney_lga = FileAttachment(\n \"The_City_of_Sydney_Local_Government_Area.geojson\"\n).json()","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":118,"value":"jacarandaSpeciesName = \"Jacaranda mimosifolia\"","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":254,"value":"treeData = (await client.query(`SELECT * from trees`)).map((item) => ({\n ...crs.unproject(item),\n ...item\n}))","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":379,"value":"species = client.query(`SELECT SpeciesName, COUNT(*) as Count\nFROM trees\nGROUP BY SpeciesName\nORDER BY Count DESC;\n`)","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"},{"id":656,"value":"turbo = d3\n .range(clusters.length + 3)\n .map((i) => d3.interpolateTurbo((i + 2) / clusters.length))","pinned":false,"hidden":false,"mode":"ojs","author":"$undefined","summary":"$undefined","output":"$undefined","database":"$undefined"}],"files":"$W34","stdlib":"1","titling":"auto"}} 32:"$31:body"