I'm a professor of mathematics at the University of North Carolina Asheville. I've also done a fair amount of consulting work over the years focusing on scientific and data visualization.
I'm happy to be part of the first Observable Ambassador's cohort.
NC Congressional DistrictsTrivariate choropleth for racial composition in the USRacial distribution in NCWNC Zoom3D Choropleth for NC County PopulationsNC CountiesTriangulated Canadian Provinces (separate)Triangulated NC CountiesAn X3D GlobeCanadian Elections 3DElectoral Results TilegramThe new Electoral CollegeElectoral MapGPX rides with Leaflet and OSMOld encoded polyline rides with LeafletGPX rides with Maplibre and MaptilerBuncombe county votingThe NC Congressional redistricting battleHexapolis 538Zillow Home PricesSetting up HexapolisCOVID curvesThirty day Map Challenge - Day 1Simple grid cartogram2020 Census Apportionment TilegramMass shootings in the USHBCUsNC State Legislative Elections 2022Hierarchical Structure of the US RegionsIndigenous territories of the SoutheastD3.force to desired positionPopulation Choropleth for the Contiguous US StatesPlotting a few points on a mapMutliple bubble maps for CSV dataWorld population bubble mapReproductive rights and ... ??Gerrymandering Hexapolis by handVisualizations of gun ownership dataIncome inequality in North Carolina
WNC Surround
wnc_surround = {
let map = d3
.create("svg")
.attr("width", map_width)
.attr("height", map_height)
.style('border', 'solid 2px black');
let county_group = map
.append("g")
.selectAll('path')
.data(counties.features)
.enter()
.append('path')
.attr('d', geoGenerator)
.style('stroke', 'black')
.style('stroke-width', '1px')
.style('stroke-opacity', 0.2)
.style('fill', function(d) {
let cases = d.properties.cases;
if (cases == 0) {
return 'white';
} else {
let s = 0.6;
if (d.properties.STATEFP == '37') {
return d3.interpolateBlues((d.properties.cases / max_cases) ** s);
} else {
return d3.interpolateReds((d.properties.cases / max_cases) ** s);
}
}
})
.on('mouseenter', function() {
d3.select(this)
.style('stroke-width', '4px')
.style('stroke-opacity', 0.8);
})
.on('mouseleave', function() {
d3.select(this)
.style('stroke-width', '1px')
.style('stroke-opacity', 0.2);
})
.attr('title', function(d) {
return `${
d.properties.NAME
} County, ${get_state(d.properties.STATEFP)}<br /> ${d.properties.cases} cases and ${d.properties.deaths} deaths<br />as of April 24`;
});
county_group.nodes().forEach(tippy);
map
.append("g")
.selectAll('path')
.data(states.features)
.enter()
.append('path')
.attr('d', geoGenerator)
.style('stroke', 'black')
.style('stroke-width', '3px')
.style('opacity', 0.7)
.style('fill', 'none');
let road_group = map.append("g");
road_group
.selectAll('path')
.data(roads.features)
.enter()
.append('path')
.attr('d', geoGenerator)
.style('fill', 'none')
.style('stroke-width', '4')
.style('stroke', '#ffffff')
.style('opacity', '0.9')
.attr('pointer-events', 'none');
let road_group2 = map.append("g");
road_group2
.selectAll('path')
.data(roads.features)
.enter()
.append('path')
.attr('d', geoGenerator)
.style('fill', 'none')
.style('stroke-width', '1.5')
.style('stroke', '#333')
.style('opacity', '0.7')
.attr('pointer-events', 'none');
map
.append('g')
.selectAll('circle')
.data(cities.features)
.enter()
.append('circle')
.attr('cx', function(d) {
let x =
projection.scale() * d.geometry.coordinates[0] +
projection.translate()[0];
return x;
})
.attr('cy', function(d) {
let y =
-projection.scale() * d.geometry.coordinates[1] +
projection.translate()[1];
return y;
})
.attr('r', 5)
.attr('fill', 'black');
map
.append('g')
.selectAll('text')
.data(cities.features)
.enter()
.append('text')
.attr('x', function(d) {
let x =
projection.scale() * d.geometry.coordinates[0] +
projection.translate()[0];
return x;
})
.attr('y', function(d) {
let y =
-projection.scale() * d.geometry.coordinates[1] +
projection.translate()[1];
return y;
})
.attr('dx', 8)
.attr('dy', function(d) {
if (d.properties.NAME == 'Atlanta') {
return 0;
} else if (d.properties.NAME == 'Knoxville') {
return 8;
} else {
return -5;
}
})
.text(d => d.properties.NAME)
.style('fill', function(d) {
if (d.properties.NAME == 'Atlanta') {
return 'white';
} else {
return 'black';
}
})
.style('font-size', '12px')
.attr('pointer-events', 'none');
return map.node();
}
geoGenerator = d3.geoPath().projection(projection)
projection = d3
.geoIdentity()
.reflectY(true)
.fitSize([map_width, map_height], bounds)
max_cases = d3.max(counties.features.map(f => f.properties.cases))
cities = {
let cities = topojson.feature(map_file, map_file.objects["cities"]);
cities.features = cities.features.filter(
d =>
[
"Asheville",
"Athens",
"Atlanta",
"Charlotte",
"Columbia",
"Knoxville"
].indexOf(d.properties.NAME) > -1
);
return cities;
}
roads = topojson.feature(map_file, map_file.objects["roads"])
function get_state(fip) {
if (fip == '13') {
return 'GA';
} else if (fip == '37') {
return 'NC';
} else if (fip == '45') {
return 'SC';
} else if (fip == '47') {
return 'TN';
}
}
counties = topojson.feature(map_file, map_file.objects["counties"])
states = topojson.feature(map_file, map_file.objects["states"])
bounds = {
let xmin = -482000;
let xmax = -57000;
let ymin = 3538010;
let ymax = 3859300;
return {
type: "Feature",
geometry: {
type: "LineString",
coordinates: [[xmin, ymin], [xmax, ymax]]
},
aspect: (ymax - ymin) / (xmax - xmin)
};
}
// This map file is the only data file.
// NY Times COVID data is embedded as properties
// in the counties layer, which is fine since we're
// intersted in a snapshot in time.
map_file = FileAttachment('wnc_surround_aea@4.json').json()
d3 = require('d3@5')
topojson = require("topojson-client@3")
tippy = require("https://unpkg.com/tippy.js@2.5.4/dist/tippy.all.min.js")
map_width = 0.8 * width
map_height = bounds.aspect * map_width
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
