Published
Edited
Jul 20, 2021
map = {
let h = (width<600) ? width + 200: width * 0.75,
z = (width<600) ? 6.5 : 7,
container = DOM.element('div', { style: `width:${width}px;height:${h}px` });
yield container;
let map = L.map(container)
.setView([43.68, -70.26], 13)
// initializes the map, sets zoom & coordinates
let osmLayer = L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}@2x.png', {
attribution: '© <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
}).addTo(map);
let parcelOverlay = L.geoJson(parcelCollection, {
pointToLayer: function (feature, latlng) {
let val21 = feature.properties.val21.taxableValue,
val20 = feature.properties.val20 ? feature.properties.val20.taxableValue : null,
c = (val20 && (val20 > 0)) ?
( (val21>=val20) ? colorRamp((val21-val20)/val20) : '#542788') : '#fff';
return L.circleMarker(latlng, {
radius: 2,
color: "#000",
weight: 0,
opacity: 0.8,
fillOpacity: 1,
fillColor: c
});
},
onEachFeature: function(feature, layer) {
let val21 = feature.properties.val21.taxableValue,
val20 = feature.properties.val20 ? feature.properties.val20.taxableValue : 'N/A',
pctChange = feature.properties.val20 ? (100*(val21-val20)/val20).toFixed(2) : 'N/A';
layer.bindTooltip(
'<h4>'+feature.properties.address+'</h4>' +
'<p>Total taxable value, 2020: $'+ val20 +
'<br/>Total taxable value, 2021: $' + val21 +
'<br/>Percent change: ' + pctChange + '%</p>'
)}
}).addTo(map);
map.on('zoomend', function() {
var currentZoom = map.getZoom();
let z = (currentZoom > 14) ? 5 : 2;
let s = (currentZoom > 15) ? 1 : 0;
parcelOverlay.eachLayer(function (marker) { marker.setRadius(z); marker.setStyle({weight: s}); });
});
let legend = L.control({position: 'bottomleft'})
legend.onAdd = function (map) {var div = L.DomUtil.create('div', 'legend'); return l};
legend.addTo(map);
}
md`# Taxable value per acre, 2021
This map illustrates the ratio of each parcel's taxable value to its acreage, according to the assessor's database. Smaller parcels on the Portland peninsula generally have higher taxable values and lower land areas, generating a higher value per acre.
Hover over a point to see assessment details from the assessor's database.`
valuePerAcreMap = {
let h = (width<600) ? width + 200: width * 0.75,
z = (width<600) ? 6.5 : 7,
container = DOM.element('div', { style: `width:${width}px;height:${h}px` });
yield container;
let valuePerAcreMap = L.map(container)
.setView([43.68, -70.26], 13)
// initializes the map, sets zoom & coordinates
let osmLayer = L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}@2x.png', {
attribution: '© <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
}).addTo(valuePerAcreMap);
let parcelOverlay = L.geoJson(parcelCollection, {
pointToLayer: function (feature, latlng) {
let val21 = feature.properties.val21.taxableValue,
a = feature.properties.acreage,
c = (a > 0) ?
colorRamp2(val21/a) : '#fff';
return L.circleMarker(latlng, {
radius: 1.5,
color: "#000",
weight: 0,
opacity: 0.8,
fillOpacity: 1,
fillColor: c
});
},
onEachFeature: function(feature, layer) {
let val21 = feature.properties.val21.taxableValue,
a = feature.properties.acreage,
vpa = (a>0) ? (val21/a).toFixed(2) : 'N/A';
layer.bindTooltip(
'<h4>'+feature.properties.address+'</h4>' +
'<p>Total taxable value, 2021: $'+ internationalNumberFormat.format(val21) +
'<br/>Acreage: ' + a + ' acres' +
'<br/>Per acre: $' + internationalNumberFormat.format(vpa) + '</p>'
)}
}).addTo(valuePerAcreMap);
valuePerAcreMap.on('zoomend', function() {
var currentZoom = map.getZoom();
let z = (currentZoom > 14) ? 5 : 2;
let s = (currentZoom > 15) ? 1 : 0;
parcelOverlay.eachLayer(function (marker) { marker.setRadius(z); marker.setStyle({weight: s}); });
});
let legend = L.control({position: 'bottomleft'})
legend.onAdd = function (map) {var div = L.DomUtil.create('div', 'legend'); return l2};
legend.addTo(valuePerAcreMap);
}
L = require('leaflet@1.2.0')
html`<link href='${resolve('leaflet@1.2.0/dist/leaflet.css')}' rel='stylesheet' />`
topojson = require("topojson-client@3")
parcelCollection = {
let a = new Object;
a.type = "FeatureCollection";
a.features = parcelGeo;
yield a;
}
parcelGeo = parcelFile.map( d => {
let o = new Object;
o.type = "Feature";
o.properties = d;
o.geometry = {"type":"Point", "coordinates": [+d.lng,+d.lat]};
return o;
});
parcelFile = FileAttachment("assessmentdata.json").json()
import {legend} from "@d3/color-legend"
colorRamp = d3.scaleLinear()
.domain([0,0.52,3])
.range([ "#2166ac", "#ffffbf", "#b2182b"])
colorRamp2 = d3.scaleLinear()
.domain([100000,10000000,40000000])
.range([ "#b3cde3", "#756bb1",'#b30000'])
internationalNumberFormat = new Intl.NumberFormat('en-US')
l2 = legend({
color: colorRamp2,
title: "Taxable value per acre, 2021",
tickValues : [1000000,10000000,40000000],
tickFormat: d3.format("$,.1s")
})
l = legend({
color: colorRamp,
title: "% in total assessed value, 2020 to 2021",
tickFormat: d => (d*100)+"%"
})
d3 = require('d3@5.0')
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