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.
Published
Edited
Aug 24, 2021
2 stars
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 3DWNC SurroundElectoral Results TilegramThe new Electoral CollegeGPX 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
Electoral Map
Also listed in…
Political Issues
probability_map = {
let div = d3
.create("div")
.style("width", `${map_width}px`)
.style("height", `${height}px`)
.style("overflow", "hidden");
let svg = div
.append("svg")
.style("overflow", "hidden")
.attr("viewBox", [0, 0, map_width, height]);
let path = d3.geoPath().projection(proj);
let map = svg.append("g");
map
.selectAll("path")
.data(states.features)
.join("path")
.attr("class", "state")
.attr("d", path)
.style("fill", function (d) {
let abbr = d.properties.fips;
let dd = data.filter((o) => o.abbr == abbr);
let p;
if (dd.length > 0) {
p = parseFloat(data.filter((o) => o.abbr == abbr)[0]["pj"]);
} else {
// p = 0.5;
}
return d3.interpolateRdBu(p);
})
.style("fill-opacity", 0.7)
.attr("data-state", function (d, i) {
let abbr = d.properties.fips;
return abbr;
})
.attr("stroke-width", "1.5px")
.attr("stroke", "#ddd")
.attr("stroke-linejoin", "round")
.on("mouseenter", function (evt, d) {
// d3.selectAll('path').style('fill-opacity', 0.2);
d3.select(this).style("fill-opacity", 1);
})
.on("mouseleave", function (evt, d) {
d3.selectAll("path").style("fill-opacity", 0.7);
});
map
.selectAll("path")
.nodes()
.forEach(function (p) {
let abbr = d3.select(p).attr("data-state");
let info = data.filter((o) => o.abbr == abbr);
if (info.length > 0) {
info = info[0];
}
tippy(p, {
allowHTML: true,
content: `
<div>${info.state}</div>
<div>Biden: ${d3.format("0.2f")(100 * info.pj)}%</div>
<div>Trump: ${d3.format("0.2f")(100 * (1 - info.pj))}%</div>`
});
});
return div.node();
}
result_cnt = (covid_check, { runs: 0, biden: 0, trump: 0 })
result_map = html``
first_run = make_result_map(run_one())
function make_result_map(trial) {
let biden_count = 0;
let trump_count = 0;
trial.forEach(function(o) {
let r = o.result;
if (r == 'Trump') {
trump_count = trump_count + o.votes;
} else {
biden_count = biden_count + o.votes;
}
});
result_cnt.runs++;
if (biden_count > trump_count) {
result_cnt.biden++;
} else {
result_cnt.trump++;
}
let div = d3
.create('div')
.attr('class', 'result_container')
.style("width", `${map_width}px`)
.style("height", `${30 + height}px`)
.style('overflow', 'hidden');
let result_display = div
.append('div')
.style("width", `${map_width}px`)
.style('height', '30px')
.style('text-align', 'center')
.html(
`Biden: ${biden_count}, Trump: ${trump_count} <br /> Percentage of Biden wins: ${
result_cnt.biden
} /
${result_cnt.runs} = ${d3.format('0.2f')(
(100 * result_cnt.biden) / result_cnt.runs
)}%`
);
let svg = div
.append('svg')
.style('overflow', 'hidden')
.attr("viewBox", [0, 0, map_width, height]);
let path = d3.geoPath().projection(proj);
let map = svg.append('g');
map
.selectAll("path")
.data(states.features)
.join("path")
.attr('class', 'state')
.attr('d', path)
.style("fill", function(d) {
let abbr = d.properties.fips;
let dd = trial.filter(o => o.abbr == abbr);
let p;
if (dd.length > 0 && dd[0].result == "Biden") {
p = 1;
} else {
p = 0;
}
return d3.interpolateRdBu(p);
})
.style('fill-opacity', 0.7)
.attr('data-state', function(d, i) {
let abbr = d.properties.fips;
return abbr;
})
.attr("stroke-width", '1.5px')
.attr("stroke", "#ddd")
.attr("stroke-linejoin", "round");
d3.selectAll('.result_container').remove();
d3.select(result_map).append(() => div.node());
}
function run_one(covid = false) {
let results = [];
let r, p;
if (covid) {
let c = Math.random();
if (c < 0.8) {
p = 2;
} else {
p = 1;
}
} else {
p = 1;
}
for (let i = 0; i < data.length; i++) {
let c = Math.random();
if (c < data[i].pj ** p) {
r = 'Biden';
} else {
r = 'Trump';
}
results.push(Object.assign({ result: r }, data[i]));
}
return results;
}
proj = d3
.geoIdentity()
.reflectY(true)
.fitSize([map_width, height], states)
map_width = 0.75 * width
height = 0.625 * map_width
Type JavaScript, then Shift-Enter. Ctrl-space for more options. Arrow ↑/↓ to switch modes.
data = {
let data = await FileAttachment(
"fivethirtyeight_electoral_probabilities@1.csv"
).csv();
data.forEach(o => {
o.pj = parseFloat(o.pj);
o.votes = parseInt(o.votes);
});
return data;
}
states = {
let map_file = await FileAttachment("states.json").json();
let states = topojson.feature(map_file, map_file.objects.states);
return states;
}
import { button, checkbox } from "@jashkenas/inputs"
topojson = require("topojson-client@3")
tippy = require("tippy.js@6")
d3 = require('d3@6')
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.
